I was just driving to work last Friday and after about 5 mins. the RPMs started going up and down between 1500 & 2000 RPMs anytime that the car was idling. It sounded like I was pressing the accelerator even though my foot wasn't near it. Any ideas on what this might be caused by or how to fix? Thank you to everyone in advance for their help!

 

ECU or TB is toast, seen this happen to a 350Z before

 

Could also be a bad IACV. If the IACV is toast, then it could have also shorted out the ECU. Be sure to check both before only replacing one of them.

You'll know an ECU is bad with a visual inspection. IACV diagnostic needs a multimeter, I think...

 

OP what year is your car?

If the OP has an 02/3, this would not apply.

 

Correct. Sorry about that. My suggestion was for 00-01.

 

What are the visual cues that I'm looking for on the ECU? Thanks again for the help!

 

You'll probably see some burnt chips or connections that don't quite look right. It may also have a burnt smell to it. You can access it from the p/s adjacent to under the glove box. It's in the middle.

check out this thread for some pics. https://maxima.org/forums/5th-genera...d-seconds.html

Some are broken links, but you should get the idea.

Probably should have asked before, but did you try to pull any codes, or is your SES light on?