I haven't had my Durango long ('99 5.2)and haven't driven it much. Basically bought it for a toy to pull around other toys and go camping and such. When I'm cruising down the highway in O.D. the RPM'S jump up and down a bit. It's not like it's shifting out of overdrive because it doesn't rev that high but it's definitely fluctuating. I turn off the overdrive and the RPM'S stay steady then. I replaced the TPS and didn't reset the computer. Drove it down the road aways and it seemed to be fixed. But I drove it again a couple days later and it started doing it again. Any thoughts or tips on diagnosis would be appreciated.
Thanks,
Jeremy

 

Sorry. Title is supposed to read RPM'S fluctuating in O.D.

 

Try changing out the speed sensor on the tail of the transmission. then make sure you reset the PCM before you drive it.

 

Okay. Thanks. I'll try that. I appreciate it.

 

How did you make out with this????

 

I haven't had a chance to mess with it yet. I also noticed there are two sensors plugged into the exhaust that the wires have been severed to. I need to crawl under another Durango and see how they hook back up. I'll let you know what I find out regarding the speed sensor. Thanks.

 

They would be the upstream and downstream oxygen sensors...

 

Finally got around to taking care of this. Crawled underneath and found the wires bare going to the connecter on the tranny output sensor. Went to the local pull a part and got the sensor and wiring. Picked up a couple O2 sensors while I was at it. Replaced everything, repaired wiring, cleared codes. Drove it for about 20 minutes and so far so good. Steady RPM'S in overdrive and throughout. Thanks for pointing me in the right direction! Much appreciated!

 

Not a problem... glad you got it fixed!

 

Also, in case your issue comes back after making all these changes, you may want to look at your TPS sensor again. It's known that replacement TPS can be bad. This is the sensor that is causing the fluctuations and rpm surging issues.