# ZZP downpipe/mid pipe.



## Thebigzeus (Dec 2, 2018)

It does not appear if you have a tune, correct.


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## PAChevyCruze (May 29, 2016)

Thebigzeus said:


> It does not appear if you have a tune, correct.


Correct. Theres a few more things I wanted to add before tuning. But, I guess I have to move things up. I have until may when it gets inspected.


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## knightryderx2 (Sep 5, 2021)

The cat that is monitored is in the downpipe. Since that cat is gone that is what trips the CEL. The midpipe cat is just to clean the exhaust gases up a bit more it is not monitored. A tune turns off the codes associated with a failed cat so the computer doesn't throw a CEL when it sees those codes. Most states that do emissions also read the ECU for codes so you will have to check with your tuner if the codes are still detectable in that case. Also you will probably fail the visual inspection because our primary cat is gone.


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## AutumnCruzeRS (Sep 10, 2012)

Just install cat before inspection and then reinstall the down pipe after a pass.


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## PAChevyCruze (May 29, 2016)

AutumnCruzeRS said:


> Just install cat before inspection and then reinstall the down pipe after a pass.


Thought about that. LOL Hopefully, I get what I want done by may (Inspection time) and get the tune on. All Im planning on doing within a month is the ported ZZP intake manifold that would be needed in the tune.


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## PAChevyCruze (May 29, 2016)

Ok, been thinking about this. I used a 02 bung extender on my Vibe GT when it threw the sensor code and it worked like a charm. Would this work with the ZZP high flow cat on the Cruze? It already has an extended downstream O2 bung, though, so I have no idea why the light is on. I dont think I damaged the sensor when I removed it. 🤷‍♂️


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## knightryderx2 (Sep 5, 2021)

PAChevyCruze said:


> Ok, been thinking about this. I used a 02 bung extender on my Vibe GT when it threw the sensor code and it worked like a charm. Would this work with the ZZP high flow cat on the Cruze? It already has an extended downstream O2 bung, though, so I have no idea why the light is on. I dont think I damaged the sensor when I removed it. 🤷‍♂️


The extender for O2 sensors are hit or miss, but they do work most times. It really wouldn't hurt to try. 

Like I said in the previous post the light is on because the primary cat is gone and this is throwing off the readings in the ECU, plan and simple. The cat you removed is the cat that is monitored, the midpipe cat is not monitored. This is why the light is on.

As far as your inspection goes it doesn't matter if you disable the code with a tune or make it go away with the extender. You will fail the visual inspection because your primary cat is gone. The only way to guarantee you passing is to put the stock downpipe in or if you know someone that can hook you up. I really don't know how serious your inspections are there. Im in Missouri and most of our smaller shops that do inspections let things like this slide as long as its not leaking or something crazy that backwoods Bob put together. Also there may be a friend that has a friend that has a uncle or cousin that works at a shop so we can usually get hooked up.


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## PAChevyCruze (May 29, 2016)

knightryderx2 said:


> The extender for O2 sensors are hit or miss, but they do work most times. It really wouldn't hurt to try.
> 
> Like I said in the previous post the light is on because the primary cat is gone and this is throwing off the readings in the ECU, plan and simple. The cat you removed is the cat that is monitored, the midpipe cat is not monitored. This is why the light is on.
> 
> As far as your inspection goes it doesn't matter if you disable the code with a tune or make it go away with the extender. You will fail the visual inspection because your primary cat is gone. The only way to guarantee you passing is to put the stock downpipe in or if you know someone that can hook you up. I really don't know how serious your inspections are there. Im in Missouri and most of our smaller shops that do inspections let things like this slide as long as its not leaking or something crazy that backwoods Bob put together. Also there may be a friend that has a friend that has a uncle or cousin that works at a shop so we can usually get hooked up.


Im not sure how strict they are on the primary cat being there or not. I figured if it has a cat, it will pass as long as it doesnt throw a code. I guess I'll be making phone calls before inspection time.  🖖


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