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2001 nissan maxima 146,000


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the idle is surging, the dealership says $1000 to replace idle air control valve and all O2 sensors and it may or may not work. my backyard mechanic has no idea but is willing to take a shot at fixing it, car runs okay but occasionally stalls and the idle surges. the internet says you can drive it like this for years and replace the IAC valve if you want but skip the O2 sensors. what should i do? car has 146,000 and is very well loved. best



Disconnect the electrical wires to the idle air control valve. Idle the engine. Does the rpm surge? If yes, then, the problem isn’t the iac valve. If it doesn’t surge, clean the iac valve with Throttle Body Cleaner.

hmmmm…I didn’t think you could do that & have the engine idle. I pulled the plug on my IAC once and the car promptly stalled. Would it have restarted without the IAC plugged in? I more or less get how they work as a single part but I guess I don’t necessarily get the systemic picture.

surging indicates variable air and fuel mixture, so look for air leaks in the intake hoses, the MAP or other sensors for fuel mix may be trying to overcome air leaks and causing this. Sometimes cleaning the sensors, very delicate, can also help. Vaccuum hoses, intake attachments, and any air hoses can be problems, and of course hard to find, sometimes people use a little water spray or oil to see if it stop a leak temporarily. Those pleated hoses are candidates for cracks to. I had similar problem with my wifes BMW, and found a bad inlet hose. Replace and problem gone.