# Engine woes. Stumped...



## Saidog24 (Sep 24, 2017)

Hey guys. I've done extensive research up to this point but not sure what to do at this point... so looking for advice. I have a 2011 eco automatic with 86000 miles. I bought the car brand new. About 3 weeks ago, the car overheated on my way home from work. Turned out to be a bad thermostat and thermostat housing. My local mechanic fixed that but then the very next day it threw the CEL. Took it back to my mechanic and he told me it was the P1101 code. I checked for the orange check valve in the intake manifold and it was not visible so I broke down and bought a new manifold. I replaced the pcv valve a little over a year ago but replaced that as well (for 2nd time) as well as the corrugated hose going from the manifold to the turbo. The car had all the usual symptoms, rough idle, down on power etc. Now that I've replaced everything, it is much better (rough idle is gone and restored power) but it is still throwing the check engine light (same code) and still feels a little down on power. I just don't know where to go from here and neither does my local mechanic. I'm afraid if I take it to the dealer they are going to try replacing what I've done. Feels like a wild goose chase at this point. Also seems odd it happened right after the overheating issue. Does anyone have any other advice? Thanks for any help in advance!


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## Robby (Mar 1, 2013)

P1101 is a maf sensor code, but can be caused by a pcv or check valve as you discovered.

In this case though, my first thought is along the lines of a aftermarket (read K&N or equivalent) air filter......so, is your filter stock and clean?
From there, the next look see is between the maf and the throttle body...specifically the hose allowing any leakage between the two.

I'll hold there for now.

Rob


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## Saidog24 (Sep 24, 2017)

She is bone stock but i will look at my filter shortly and see what it looks like.


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## ChevyGuy (Dec 13, 2014)

The P1101: The ECM compares actual airflow based on throttle position to a calculated airflow based on MAP and MAF sensors. The ECM sets a code if it detects the actual airflow is greater than the calculated values. The entire air intake system needs to be inspected for leaks or restrictions. The exhaust system as well. It even mentions the turbo wastegate as a possible source. A number of members have experience problems with the latter.

But in this case, I'd suggest re-checking the mechanic's work.


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## Saidog24 (Sep 24, 2017)

So the new code that it is throwing is P0033. It was saying turbo bypass diverter valve. I replaced that as it was only $25 bucks on rock auto, however after deleting the code afterwards, it continues to throw the p0033 code. Does anyone have experience or input regarding this code?


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## ChevyGuy (Dec 13, 2014)

P0033 - the ECM detects an open circuit controlling the turbo bypass diverter valve.

Make sure there's no corrosion in the connector or that mice haven't been chewing on the wires.


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## Saidog24 (Sep 24, 2017)

Checked all the connections today. Everything is in tact. Guess I'm going to have to surrender it to the dealership for diagnosis... ?


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## ChevyGuy (Dec 13, 2014)

Saidog24 said:


> Checked all the connections today. Everything is in tact. Guess I'm going to have to surrender it to the dealership for diagnosis... ?


Sounds like a plan. The next part is the ECM itself - not cheap. You've reached a logical end to throwing parts at it - time to do deeper tests.


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## Saidog24 (Sep 24, 2017)

ChevyGuy said:


> Sounds like a plan. The next part is the ECM itself - not cheap. You've reached a logical end to throwing parts at it - time to do deeper tests.


Thanks. I'm going to call the dealership tomoorw. I'll report back when I get more info.


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