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Discussion Starter · #1 ·
Hey guys,

I've been having some issues with rough idle after stopping the car and putting it in the neutral (manual gearbox). I've already replaced the MAF and the Idle control valve but that didn't help. I've also replaced the O-ring on Disa valve. The idle sometimes falls really low and the car even stalled a few times, but that's pretty rare. I've also had a mechanic check for vacuum leaks in the intake but he didn't find any. The lambda probes are also in normal shape.
I noticed that the car makes a weird hissing sound if I very lightly tap the gas pedal. I am attaching a video. Does it sound familiar to someone?

https://youtu.be/PFfYTIFMsQw
 

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Sounds like the CCV system under the manifold may be going. Mine made a funny squeaking noise under light throttle and would occasionally missfire until I replaced it.
A bit of a pain to get at but definitely worth doing as the car runs noticeably better now.
Also, I take it you have checked there are no splits or cracks anywhere in the rubber intake hoses between the MAF and the throttle body as they can cause unmetered air to get in and create a missfire as well.
Best of luck.
 
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