2000 Engine Problems

My buddies 2000 Cherokee is having some troubles, we were trying to diagnose it. He said when he is driving along the rpms will sometimes drop from 2000 or 3000 to pretty much idle and then comes right back up, so it pretty much falls on its face while he is driving. When its idling it will idle really low and almost die. He isn't getting any codes for anything except the O2 sensor, but he just replaced it yesterday, and the problem was happening before this and after this. This is an intermittent problem, and doesn't happen all the time. What are you guys thinking? Thanks, Christian

Search for O2 sensors here in this forum. I don't have the experience, but remember reading something related, I think it was somehting with the brand of...

Boris

It sounds like either the ignition or fuel injectors are shutting down for a second.

CPS intermittency would cut the ignition. Not sure what is being used to trigger the injectors on the 2000 since they eliminated the distributor. I would imagine the CPS could be used for both functions.

Has your friend "washed" his engine lately? If so he might want to check to see if any liquid made it's way into the CPS connector/sensor interface.

Just throwing out ideas.

MAP

Not sure if he has "washed" it at all. I read something about the o2 sensor that sounded similar, but his was doing it before and after the install, so that is why we thought it might be something different. The new O2 Sensor is a Bosh sensor btw. Christian