I have a 1997 Pathfinder SE 4x4...it just started having a problem with the RPMS. At 45MPH and then at 70MPH the RPMs surge. The speed stays the same, but the RPMs jump up for a few seconds and then go back down. I've taken it to three shops, including a Nissan dealer and no one can find the problem. I replaced the TPS switch but that didn't help...any suggestions?

Just curious why you replaced the TPS sensor? That would be my first idea to check, but it is adjustable and pretty tricky to get positioned exactly right. Did you try adjusting the old TPS or adjust the new one when you put it in?

The diagnostic came up with the code for the TPS sensor...that's why the guy at the garage changed it.

I've had a TPS sensor error code plus A/T gear ratio errors that were all fixed by adjusting the TPS sensor. When he put the new one in did he follow the Nissan adjustment procedures or just bolt it on like a Ford TPS? If this wasn't a Nissan dealership there's a good chance it needs to be adjusted properly.