2000 Nissan Maxima with approx. 167k miles on it.
Had this issue initially about 4 months ago. Would pull up to red light and when car in neutral while waiting for light to change, about 30-or-so seconds into sitting there in neutral, RPMs would dip below 500 and car would stall.
Bought Mass Air Flow Sensor cleaner and cleaned the unit. Seemed to resolve the problem.
Now it’s 4-or-so months later and the same thing began occurring yesterday out of the blue & continues again today. Car doesn’t stall while sitting still if in Drive… just happens when in Neutral & I’m assuming will likely stall while idling in Park, too.
No problems at all running or cranking or anything like that. No error codes were detected by AutoZone 4-5 months ago when the problem initially occurred. Going to take it by there again today during lunch to see if any error codes thrown this time around… my guess is nothing will turn-up again error code-wise.
Clean Mass Air Flow Sensor again with the special spray cleaner & see what happens? Just go ahead and replace the Mass Air Flow Sensor? Could this be something else? Everything with the car otherwise seems wonderful, aside from the stalling while idling in Neutral after sitting still for 30-45 seconds.
Can’t remember the last time plugs were replaced in the car… probably should do that regardless of whether or not that’s part of the issue or not.
Any suggestions are greatly appreciated!
I would be more inclined to suspect the Idle Air Control valve before the MAF sensor.
If it were a MAF sensor problem, it would effect the engine performance other than at idle. And I would think there would be codes showing up indicating the engine is running too lean or rich in all cylinders.
An IAC valve on the otherhand can cause the engine to stall at idle. This valve moves to different positions to control the engine idle speed depending on the load imposed on the engine while idling. So for example if the AC is turned on while idling, the IAC valve moves to a position that prevents the engine from stalling for that load imposed on the engine. It could be that when in neutral and idling, the IAC valve goes to the proper position for that idle condition, but the longer it remains at that position the IAC valve malfunctions and the engine stalls.
A quick way to test for this is, when you sense the engine is about to stall, with your left foot firmly on the brake pedal, slightly step on the gas pedal. If doing this prevents the engine from stalling, it pretty much indicates the problem is with the IAC valve.
Tester