# 1999 Altima stalls at idle after reaching normal operating temps



## Kebast (Mar 11, 2015)

I have a 1999 Altima that runs fine at highway speeds, but will stall in stop & go traffic. I can make a 30 mile commute to work, but can't make a 3 mile drive through town. The issue has gotten worse over the past 4 months. The only other symptom is that temp gauge sometimes bounces around or is jittery. I have never noticed any sign of overheating though. 

The only work I've done so far is replacing the spark plugs. I didn't notice anything out of the ordinary there, other than the old plugs were very bad. That didn't make any change in the problem though.

Any idea what might be wrong?


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## Kebast (Mar 11, 2015)

*Still not fixed*

I cleaned the MAF sensor and the throttle body last weekend. This needed doing, but made no progress with my current issue. I have an Idle Air Controller Valve that I'll replace this weekend.


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## smj999smj (Jan 1, 2006)

Make sure the base idle and ignition timing is properly adjusted per the service manual procedure. If the base idle is too low, the IACV-AAC valve will not operate properly. Also, use carb cleaner with the engine running to spray around the intake manifold gasket to check for leaks; they were a more common problem on the 97 and earlier KA24DE's, which had a different port design, but still wouldn't hurt to check.


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## Kebast (Mar 11, 2015)

*Bad Cat Converter*

The issue ended up being a bad forward catalytic converter. The one that bolts on near the manifold. It was collapsing once it got hot. Ambient air flow at 40mph+ was enough to keep it working. At idle, it got too hot (180F+).


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