hi all hows everyone doing. i just got a custom cat back exhaust with stock muffler but no resonator put on my 03 nissan 350z a/t and now the rpm is idling around 400-500. i reset the ecu and everything but still problem. i open the hood while the engine is running and i hear a air leaking sound (pshhh) around the pcv valve area im not sure if its the pcv leaking but its def. leaking some kind of air. And also when im on park and rev. the engine the rpm will fall all the way to about 200 rpm but quickly comes up to 400-500

Just wondering if a pcv is leaking will it cause the rpm to be low? and how do you change the pcv? is it a screw on or just pull up? sorry im new to this. thank you

 

Yes, a leaking PCV can cause idle problems if I'm not mistaken. It's probably the hose connection that has the problem. PCValves are cheap though. You can replace it and the hose, and or the little clamp faily cheap. The PCV has in nut molded in to it. It's made of plastic, so be gentle. A regular socket wrench should take it off. Right tightly, lefty loosey...

 

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it can cause idle problems only if there is a vacuum on it. Easy test would be unhook the hose to the pcv and plug the hose from the plenum and see if the problem goes away.