# Bad air intake manifold check valve diagnosis



## Trobs98 (12 mo ago)

Hi everyone, I’m trying to diagnose a bad pcv check valve in the intake manfold and was wondering if there are any signs I can look for using a scanner? (ex. Fuel trim or any sensor data). I’m getting a P0170 code, but no engine light, and I took off the pcv hose and couldn’t see the orange nipple that has been discussed in other threads, which is why I believe it’s that check valve that is causing the code. I have checked for any apparent cracks in vacuum hoses and there doesn’t seem to be any and the actual pcv regulator diaphragm doesn’t seem to have broken as there is no air being pulled in. Would love all your expertise. Thanks.


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## JLL (Sep 12, 2017)

Search is definitely your friend on this question. There are at least a dozen threads on this topic.

2011-2016 Cruze 1.4 PCV Valve Cover/Intake Manifold Issues

Sorry the link won't copy. But search that.


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