# Gen2 Diesel Muffler Delete



## MP81 (Jul 20, 2015)

Do the Gen 2 diesels have a muffler? The Gen 1 diesels did not have one.

I wouldn't hold your breath on being able to delete - thus far, there has been no delete made available for the Gen 2 - and that was before the EPA crackdown that saw the Gen 1 deletes become extremely scarce (and expensive). Tuning would be a major issue in deleting the Gen 2 - it's proving extremely difficult to crack.


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## BodhiBenz1987 (Jan 13, 2018)

MP81 said:


> Do the Gen 2 diesels have a muffler? The Gen 1 diesels did not have one.
> 
> I wouldn't hold your breath on being able to delete - thus far, there has been no delete made available for the Gen 2 - and that was before the EPA crackdown that saw the Gen 1 deletes become extremely scarce (and expensive). Tuning would be a major issue in deleting the Gen 2 - it's proving extremely difficult to crack.


The Gen 2 has what looks like a resonator/muffler but is part of the SCR system. It might have a muffling effect but isn't really a muffler and couldn't be removed without the full "modification". I am guessing the DOC/DPF have enough muffling effect that it wouldn't make much difference to have a muffler downstream.


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## Rivergoer (Mar 30, 2017)

Another approach...some here have reported switching to a Cold Air Intake (CAI) provides some added turbo sound and diesel rumble.


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## FlagrantBacon94 (Apr 8, 2020)

I had a good look under my vehicle when installing splash guards but didn’t really pay attention to anything but what I was doing. I know that the gen1 gas models had a massive muffler that ran down the middle of the vehicle. But I don’t think I remember seeing anything but just a regular pipe on mine when I had it off the ground. 



MP81 said:


> Do the Gen 2 diesels have a muffler? The Gen 1 diesels did not have one.
> 
> I wouldn't hold your breath on being able to delete - thus far, there has been no delete made available for the Gen 2 - and that was before the EPA crackdown that saw the Gen 1 deletes become extremely scarce (and expensive). Tuning would be a major issue in deleting the Gen 2 - it's proving extremely difficult to crack.


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## MP81 (Jul 20, 2015)

FlagrantBacon94 said:


> I had a good look under my vehicle when installing splash guards but didn’t really pay attention to anything but what I was doing. I know that the gen1 gas models had a massive muffler that ran down the middle of the vehicle. But I don’t think I remember seeing anything but just a regular pipe on mine when I had it off the ground.





BodhiBenz1987 said:


> The Gen 2 has what looks like a resonator/muffler but is part of the SCR system. It might have a muffling effect but isn't really a muffler and couldn't be removed without the full "modification". I am guessing the DOC/DPF have enough muffling effect that it wouldn't make much difference to have a muffler downstream.


Okay, so it sounds like it's similar to the Gen 1s - SCR is the last piece of the exhaust, middle-ish of the car. Looks like a big resonator, but it's the SCR and definitely is needed on non-delete vehicles.



Rivergoer said:


> Another approach...some here have reported switching to a Cold Air Intake (CAI) provides some added turbo sound and diesel rumble.


You would be correct. The amount of turbo noise the car has (especially when you let off the throttle quickly) with a "CAI" (really more of a short-ram) is pretty crazy, but not surprising, given the turbo is like 8 inches away from the cone.

@Snipesy posted a good video of his with a K&N intake (it's the one on ours, I bought it off him, haha) on his 1st gen CTD:


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## Snipesy (Dec 7, 2015)

I miss hearing the flutter


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## Snipesy (Dec 7, 2015)

Don’t forget my VGT video which has an under hood mic for dramatic effect.






I highly doubt the gen 2 will sound that way but hey cool turbo noise.


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## FlagrantBacon94 (Apr 8, 2020)

So, I actually had to get under my car today because the oil drain door somehow decided it didn't want to stay connected to the entire panel. I did see what looked like a small muffler around where the cup holders would be. If this is actually a muffler I'm not 100% sure since I couldn't really get close enough to see everything there.



MP81 said:


> Do the Gen 2 diesels have a muffler? The Gen 1 diesels did not have one.
> 
> I wouldn't hold your breath on being able to delete - thus far, there has been no delete made available for the Gen 2 - and that was before the EPA crackdown that saw the Gen 1 deletes become extremely scarce (and expensive). Tuning would be a major issue in deleting the Gen 2 - it's proving extremely difficult to crack.


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## FlagrantBacon94 (Apr 8, 2020)

Snipesy said:


> I miss hearing the flutter


Love hearing it on the modified trucks. happily the truck pull at the county fair this past year had a free truck pull event.


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## MP81 (Jul 20, 2015)

If you get a chance, can you snap a few pics of the exhaust system?

We have a really good thread that shows the entirety of the exhaust system (via a lift), not long after they came out, which has always been super helpful - but that is only for the Gen 1. Can't say we have anything similar to reference on the Gen 2s.

I'm expecting there to be no muffler, as GM doesn't have any mufflers on any of their other diesel products, since the turbo, DPF and SCR do such a good job of lower the exhaust decibel level.


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## FlagrantBacon94 (Apr 8, 2020)

MP81 said:


> If you get a chance, can you snap a few pics of the exhaust system?
> 
> We have a really good thread that shows the entirety of the exhaust system (via a lift), not long after they came out, which has always been super helpful - but that is only for the Gen 1. Can't say we have anything similar to reference on the Gen 2s.
> 
> I'm expecting there to be no muffler, as GM doesn't have any mufflers on any of their other diesel products, since the turbo, DPF and SCR do such a good job of lower the exhaust decibel level.


For sure. I'll grab some when I can and post the here.


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## BodhiBenz1987 (Jan 13, 2018)

MP81 said:


> If you get a chance, can you snap a few pics of the exhaust system?
> 
> We have a really good thread that shows the entirety of the exhaust system (via a lift), not long after they came out, which has always been super helpful - but that is only for the Gen 1. Can't say we have anything similar to reference on the Gen 2s.
> 
> I'm expecting there to be no muffler, as GM doesn't have any mufflers on any of their other diesel products, since the turbo, DPF and SCR do such a good job of lower the exhaust decibel level.


Here are a couple pics I took with the full pan off, that might be helpful. In hindsight I should have taken a couple of behind the engine too where the DEF injector is. The DPF can be seen in front of the engine, with the DOC out of site on top of the DPF (can be seen under the hood to the right of the turbo ... the DOC and DPF are combined in one unit. There are two EGT sensors in the DPF/DOC unit as well as the two thin tubes that attach to the rubber lines for the pressure differential sensor (you can see the tubes in the corner of the third photo). The NOx catalyst is the resonator looking things you can see at the middle of the car. The DEF injector is behind the engine and a little harder to see as it's fairly high up there. It is before the NOx catalyst. There is an NOx sensor in the tailpipe after the NOx catalyst. There is a particulate sensor just behind the flex pipe seen in the photo under the engine. And the third EGT sensor between the DPF and flex pipe. Unfortunately I didn't take clearer pics of the exhaust parts behind the car, maybe @FlagrantBacon94 could add those to round it out.


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## BodhiBenz1987 (Jan 13, 2018)

FlagrantBacon94 said:


> So, I actually had to get under my car today because the oil drain door somehow decided it didn't want to stay connected to the entire panel. I did see what looked like a small muffler around where the cup holders would be. If this is actually a muffler I'm not 100% sure since I couldn't really get close enough to see everything there.


That sounds like the NOx catalyst which is unfortunately a part of the emission system. The oil drain door on mine loves to come loose. And those screws are really hard to get "set" right. The concept of the access panel is great, makes oil changes really easy, but man, the design is a mess.


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## MP81 (Jul 20, 2015)

Snipesy said:


> Don’t forget my VGT video which has an under hood mic for dramatic effect.
> 
> 
> 
> ...


I'm not sure it's much quieter inside the car, in all actuality, haha. It's _loud_. But in a good way. Usually.

The VGT definitely makes for some very interesting transitions, since it doesn't always need to use the wastegate, and doesn't really recirc - it just changes the blade angle. Makes for a lot more constant noise.

That said - the 1.6L does have a VGT, so it should sound pretty neat.



BodhiBenz1987 said:


> Here are a couple pics I took with the full pan off, that might be helpful. In hindsight I should have taken a couple of behind the engine too where the DEF injector is. The DPF can be seen in front of the engine, with the DOC out of site on top of the DPF (can be seen under the hood to the right of the turbo ... the DOC and DPF are combined in one unit. There are two EGT sensors in the DPF/DOC unit as well as the two thin tubes that attach to the rubber lines for the pressure differential sensor (you can see the tubes in the corner of the third photo). The NOx catalyst is the resonator looking things you can see at the middle of the car. The DEF injector is behind the engine and a little harder to see as it's fairly high up there. It is before the NOx catalyst. There is an NOx sensor in the tailpipe after the NOx catalyst. There is a particulate sensor just behind the flex pipe seen in the photo under the engine. And the third EGT sensor between the DPF and flex pipe. Unfortunately I didn't take clearer pics of the exhaust parts behind the car, maybe @FlagrantBacon94 could add those to round it out.
> 
> View attachment 286275
> 
> ...


Those are a great set of shots - yeah what I see there in the middle of the car looks similar to what we see under the Gen 1s. If there is no muffler out back (I think either the sedan and hatch mufflers are clearly visible underneath), then they went the same route as their other current diesels.



BodhiBenz1987 said:


> That sounds like the NOx catalyst which is unfortunately a part of the emission system. The oil drain door on mine loves to come loose. And those screws are really hard to get "set" right. The concept of the access panel is great, makes oil changes really easy, but man, the design is a mess.


Oil drain door for...the oil pan drain plug? Or to access the oil filter?


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## Barry Allen (Apr 18, 2018)

FlagrantBacon94 said:


> At that point I’ll just straight pipe it from the turbo and be done with it.


If you remove every piece of exhaust treatment equipment (oxidation catalyst, DPF, and SCR catalyst) you will get all kinds of CELs as well as a 75 mile countdown for a defective emissions system that will cap your speed at 65mph, 55mph, 45mph, and then 4mph.

How do you plain to "straight pipe" a modern engine with all the emissions equipment?


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## BodhiBenz1987 (Jan 13, 2018)

MP81 said:


> Oil drain door for...the oil pan drain plug? Or to access the oil filter?


I meant the access panel on the underside panel held in by four screws ... I am not sure the term for the type of screw but I find it hard to get them to grab the tabs they supposed to go into.


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## MP81 (Jul 20, 2015)

Yeah - what is the access panel for? We don't get one of those on the 1st gen, but the drain plug is accessible without removing the under-engine cover. The oil filter is on the back lower passenger side of the 2.0L, sideways (cartridge-style), but it has a gutter that allows it to drain out a hole in the panel. Well, it does if it hasn't fallen off and onto your CV joint...ours is currently sitting in the basement after it did just that.


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## FlagrantBacon94 (Apr 8, 2020)

Barry Allen said:


> If you remove every piece of exhaust treatment equipment (oxidation catalyst, DPF, and SCR catalyst) you will get all kinds of CELs as well as a 75 mile countdown for a defective emissions system that will cap your speed at 65mph, 55mph, 45mph, and then 4mph.
> 
> How do you plain to "straight pipe" a modern engine with all the emissions equipment?


pickups do it all the time. if there is a kit, and i've heard there currently isn't right now, you'll need to mod the computer to thinking everything is still there. unfortunately it is illegal to do in the eyes of the EPA, but they're just money hungry turds that can suck an egg in my opinion. gen1 cruze had a fair delete kit that at least got rid of the exhaust components. i couldn't say for the EGR or anthing like that though.


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## FlagrantBacon94 (Apr 8, 2020)

BodhiBenz1987 said:


> Here are a couple pics I took with the full pan off, that might be helpful. In hindsight I should have taken a couple of behind the engine too where the DEF injector is. The DPF can be seen in front of the engine, with the DOC out of site on top of the DPF (can be seen under the hood to the right of the turbo ... the DOC and DPF are combined in one unit. There are two EGT sensors in the DPF/DOC unit as well as the two thin tubes that attach to the rubber lines for the pressure differential sensor (you can see the tubes in the corner of the third photo). The NOx catalyst is the resonator looking things you can see at the middle of the car. The DEF injector is behind the engine and a little harder to see as it's fairly high up there. It is before the NOx catalyst. There is an NOx sensor in the tailpipe after the NOx catalyst. There is a particulate sensor just behind the flex pipe seen in the photo under the engine. And the third EGT sensor between the DPF and flex pipe. Unfortunately I didn't take clearer pics of the exhaust parts behind the car, maybe @FlagrantBacon94 could add those to round it out.


I might actually be able to get my car in the air since my manager actually has his own garage and all. its just a matter or getting over there when he isn't busy and letting me use it for a few minutes.


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## BodhiBenz1987 (Jan 13, 2018)

MP81 said:


> Yeah - what is the access panel for? We don't get one of those on the 1st gen, but the drain plug is accessible without removing the under-engine cover. The oil filter is on the back lower passenger side of the 2.0L, sideways (cartridge-style), but it has a gutter that allows it to drain out a hole in the panel. Well, it does if it hasn't fallen off and onto your CV joint...ours is currently sitting in the basement after it did just that.


On the Gen 2 you have to remove the little panel to access the drain plug and filter. Here is a photo of the setup when you get the access plate off, looking up through the opening. Looking at this photo now (it's older), you can actually see the DEF injector up there too, to add to the exhaust system photos.


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## MRO1791 (Sep 2, 2016)

BodhiBenz1987 said:


> That sounds like the NOx catalyst which is unfortunately a part of the emission system. The oil drain door on mine loves to come loose. And those screws are really hard to get "set" right. The concept of the access panel is great, makes oil changes really easy, but man, the design is a mess.


It comes loose when it's not tightened, and the dealership did not properly tighten mine twice. The fix is to apply anti-seize on the fasteners, and when you tighten, go until you think it's almost too much, then it should let up and turn a bit more, that is the "lock" feature on those fasteners. My guess is the dealership has some oil change tech doing it and since these cars are so rare, and only the Diesel has that cover, they don't know to fully tighten it to get past that point to lock the fasteners. They are not your typical threaded fastener. With anti-seize, they go on my better to get to the "lock" point.


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## MRO1791 (Sep 2, 2016)

MP81 said:


> Yeah - what is the access panel for? We don't get one of those on the 1st gen, but the drain plug is accessible without removing the under-engine cover. The oil filter is on the back lower passenger side of the 2.0L, sideways (cartridge-style), but it has a gutter that allows it to drain out a hole in the panel. Well, it does if it hasn't fallen off and onto your CV joint...ours is currently sitting in the basement after it did just that.


On the Gen 2 there is an access panel that offers access to both the oil drain plug, and filter, both on the back of the oil pan. It's well laid out, and I know about the Gen 1, and the drip feature, on one of mine it had come off and I did a weld repair to fix it and put it back on. For Gen 2 the filter cap is vertical on the bottom of the engine, and has it's own drain plug. It's a pretty good layout actually.


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## FlagrantBacon94 (Apr 8, 2020)

Well, I ended up just putting my car on ramps to fix my oil drain cover. Before I got my car off the ramps I tried getting as good of a picture as I could.


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## Barry Allen (Apr 18, 2018)

FlagrantBacon94 said:


> pickups do it all the time. if there is a kit, and i've heard there currently isn't right now, you'll need to mod the computer to thinking everything is still there. unfortunately it is illegal to do in the eyes of the EPA, but they're just money hungry turds that can suck an egg in my opinion. gen1 cruze had a fair delete kit that at least got rid of the exhaust components. i couldn't say for the EGR or anthing like that though.


Pickups do it if there is a computer tune that will allow it.

You might not have noticed but the EPA has really started to crack down in tuners. In years past they just tolerated tuners who sold "off-road only" delete kits that were done to pickups that spent about 99.99% of their time on public roadways. It was a wink and a nod, and the EPA just figured it was a relative drop in the bucket of pickups sold so it wouldn't matter all that much.

Fast forward and we have discovered diesel emissions are a real serious problem, and they no longer tolerate tuning that deletes emissions equipment. They've sued several tuners and won consent agreements in court to the point that tuning is on a downward spiral. You'll see tuning that can increase power but it still leaves emissions equipment in place. No one really makes tuning to where you can delete, take off, block off, or otherwise eliminate emissions equipment. It's high cost, low margin, and the EPA will sue you for it now.


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## MP81 (Jul 20, 2015)

Barry Allen said:


> You'll see tuning that can increase power but it still leaves emissions equipment in place.


Trifecta wouldn't even tweak the tune for the CAI I put on the car (which, being a K&N, is 50-state legal). They don't want to take any chances, and I do not blame them.


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## boraz (Aug 29, 2013)

Barry Allen said:


> Pickups do it if there is a computer tune that will allow it.
> 
> You might not have noticed but the EPA has really started to crack down in tuners. In years past they just tolerated tuners who sold "off-road only" delete kits that were done to pickups that spent about 99.99% of their time on public roadways. It was a wink and a nod, and the EPA just figured it was a relative drop in the bucket of pickups sold so it wouldn't matter all that much.
> 
> Fast forward and we have discovered diesel emissions are a real serious problem, and they no longer tolerate tuning that deletes emissions equipment. They've sued several tuners and won consent agreements in court to the point that tuning is on a downward spiral. You'll see tuning that can increase power but it still leaves emissions equipment in place. No one really makes tuning to where you can delete, take off, block off, or otherwise eliminate emissions equipment. It's high cost, low margin, and the EPA will sue you for it now.


EPA has suspended all enforcement INDEFINITELY


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## boraz (Aug 29, 2013)

FlagrantBacon94 said:


> Well, I ended up just putting my car on ramps to fix my oil drain cover. Before I got my car off the ramps I tried getting as good of a picture as I could.
> 
> View attachment 286287
> View attachment 286288


is that how the car is? or did you remove 'aero panels' from either side of the exhaust tunnel?


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## 406 (Apr 5, 2019)

boraz said:


> EPA has suspended all enforcement INDEFINITELY


Please elaborate on this claim?!?


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## boraz (Aug 29, 2013)

406 said:


> Please elaborate on this claim?!?





https://www.epa.gov/sites/production/files/2020-03/documents/oecamemooncovid19implications.pdf


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## Barry Allen (Apr 18, 2018)

boraz said:


> EPA has suspended all enforcement INDEFINITELY


That's suspension of the big ticket enforcements of the clean air and clean water acts, I.E., the field personnel who are on-site enforcers at power plants, water treatment plants, etc. The suspension is to give critical operations a little bit of leeway in the coronavirus emergency. Example: a coal power plant doesn't get a delivery of some material used to wash flue gases of NOx or whatever. Well, you have to keep lights on for people, so it's overlooked for the time being. So on and so forth.

This doesn't mean engine tuners can do whatever they want now. Go ahead, but the EPA will be back to focus on them later when things begin getting closer to normal.


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## Snipesy (Dec 7, 2015)

Barry Allen said:


> This doesn't mean engine tuners can do whatever they want now. Go ahead, but the EPA will be back to focus on them later when things begin getting closer to normal.


nanananananananan nope EPA shutdown can roll coal now and kill people.


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> nanananananananan nope EPA shutdown can roll coal now and kill people.


Sure, and when the Pope dies you've got about a week to do whatever you want because you can't sin until a new one is elected, right?


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## Wantatune (Mar 28, 2020)

no check engine light for me


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## Barry Allen (Apr 18, 2018)

Wantatune said:


> no check engine light for me


Is the DPF removable to where it leaves sensors in place and it doesn't throw a CEL with stock tuning?


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## Wantatune (Mar 28, 2020)

I'm not following. Are you referring to gutting the dpf and leaving everything thing in place? If so yes. He sent me a tune for that. Still waiting on the bugs to be worked out for the stage 1 tune.


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## Barry Allen (Apr 18, 2018)

Wantatune said:


> Are you referring to gutting the dpf and leaving everything thing in place?


Yes. I want to know if the stock ECU can be used with a straight-pipe in place of the DPF, or if tuning is required.


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## Wantatune (Mar 28, 2020)

Tuning required


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## MRO1791 (Sep 2, 2016)

boraz said:


> is that how the car is? or did you remove 'aero panels' from either side of the exhaust tunnel?


Gen 2 does not have the aero panels that the Gen 1 has. Only has the panel below the engine, that is all. What you see in the pictures is what is there.


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## FlagrantBacon94 (Apr 8, 2020)

boraz said:


> is that how the car is? or did you remove 'aero panels' from either side of the exhaust tunnel?


That’s how it is. I had put it in the air using my bosses lift when it was around 5000 miles and there wasn’t any panels. The only panel is for the under side of the engine. I’m sure the gen1 is a little different.


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## FlagrantBacon94 (Apr 8, 2020)

Wantatune said:


> no check engine light for me


That’s in a gen2?


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## FlagrantBacon94 (Apr 8, 2020)

Barry Allen said:


> Yes. I want to know if the stock ECU can be used with a straight-pipe in place of the DPF, or if tuning is required.


Tuning would alway be required if there’s a sensor involved. Say for a o2 sensor; you’d have to program the computer to think it’s there and working properly if you were to take it out completely. Just an example I could come up with on the spot.


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## pandrad61 (Jul 8, 2015)

FlagrantBacon94 said:


> pickups do it all the time. if there is a kit, and i've heard there currently isn't right now, you'll need to mod the computer to thinking everything is still there. unfortunately it is illegal to do in the eyes of the EPA, but they're just money hungry turds that can suck an egg in my opinion. gen1 cruze had a fair delete kit that at least got rid of the exhaust components. i couldn't say for the EGR or anthing like that though.


Since the EPA crack down on this practice it has delete tuners in hiding. For gen one there are kits out there but not easy to get and expensive. It also disabled EGR


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## Wantatune (Mar 28, 2020)

It's alive!!! 2017 1.6l diesel. Down pipe is crude but done. Will update in the next few days any drivability issues. It's a 6spd manual, egr blocked off. Dpf removed. All sensor disconnected and no check engine light. ????


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## boraz (Aug 29, 2013)

FlagrantBacon94 said:


> That’s how it is. I had put it in the air using my bosses lift when it was around 5000 miles and there wasn’t any panels. The only panel is for the under side of the engine. I’m sure the gen1 is a little different.


yeah gen1 diesel has 'aero panels'

i know the gen2 diesel gets great mpg, just assumed it had 'aero panels' as well


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## Wannabe1.6owner (Dec 22, 2020)

Wantatune said:


> It's alive!!! 2017 1.6l diesel. Down pipe is crude but done. Will update in the next few days any drivability issues. It's a 6spd manual, egr blocked off. Dpf removed. All sensor disconnected and no check engine light. ????
> View attachment 286341


How is it holding up? I am doing my Equinox today. Trying to unhook all the sensors but I don't know what all need to stay, and what all needs to go.


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