# 92 Maxima fluctuating idle



## hofner (Aug 6, 2013)

I'll be driving at highway speed, take my foot off the gas and the RPMs start to go down, as you would expect. However, when it reaches around 1000 it then begins to fluctuate from around 1000 to 1500, back and forth, back and forth almost like a pendulum. And of course the car slows and speeds with it. What is causing this? Why isn't the RPM reducing like normal?


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## smj999smj (Jan 1, 2006)

"Surging" is often caused by a lean condition. Is this a VG30E engine? If so, the self-diagnostic system was a bit crude by today's standards, but you may want to start by checking for stored codes. Running lean can be caused by a bad O2 sensor or MAS, vacuum leaks, low fuel pressure, or a stuck open EGR valve. To check for codes:

Trouble Codes


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## hofner (Aug 6, 2013)

Thanks! This was really helpful


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