My car started acting up and finally the check engine light came on. When its cold it idles fine but once I have been driving it for about 15 min the idle fluctuates about 300rpm between 900 and 1200. When sitting still it idles rough to the point where the car shakes a little bit. Come to find out had a cracked crankcase ventilation hose. Replaced that cleared the check engine light. Light came back on. Ran the codes and it says its running lean and had a couple other ones but I can't remember what they are right now. Replaced the MAF because it was showing that at idle and when i drive its constantly adjusting up and down. That didn't fix the issue. Checked all vacuum lines and can't find a leak anywhere. I am lost as to what the problem is but the car only acts up when its been running for about 10-15 min.

Thanks for any input

 

Apparently the problem takes place when the engine goes into the closed loop mode, which usually points to a sensor problem. Let us know what the trouble codes are, and we may be able to help.

 

Ended up a bad diverter valve. Got it replaced with a new APR R1 and now the car drives fine and boosts fine. The idle is still not right. Tried to reset the throttle body and that did not fix it. The only code that is being thrown is that that the idle is too high. Went over all the vacuum lines multiple times and can not find a leak anywhere. Im lost on this one.

Thanks for the help

 

I found that if i try and pull the oil dipstick when the engine is running its sucking it back in with a good bit of pressure and the engine idle changes everytime I do this. Sounds like the PVC valve is failng.