I have a 2000 dodge dakota 4.7L v8. While im driving at constant speeds it revs up a few hundred rpms and goes back down. As well when after I drive it and put in park it revs up. When I bought this truck it did have a cold air intake and had a performance chip. And recently there seems to be an exhaust leak coming from near the manifold. Im still not sure why it revs up like this. I need help please! Thanks-Chubbs!

 

Hi and welcome to the forums.

A vacuum leak would be one cause of an erratic idle speed. It could also be a bad tps (throttle position sensor) or IAC valve (Idle Air Control).

Do you have any trouble codes? Is the check engine light on? To pull codes without a reader:

Starting with the key off, turn the key on, off, on, off then leave on. (that's to on, not start). Codes will display in the odometer window.

 

x2 on the bad TPS.

 

try cleaning the throttle body and tps

 

Did you mean to say IAC sensor? TPS is sealed and can't clean the inside or at least I wouldn't recommend it.

 

just inside the throttle body. i have seen vacuum ports plugged up and stuff

 

i have the same issue with a 2001 4.7 had at a dodge dealers and they cant find what is the cause. i me personally am getting really tried of spending 200 to 500 on this thing and not getting any where.

 

I wouldn't pay them. This is a classic example of an inexperienced mechanic. It all boils down to basic troubleshooting. Lots of mechanics can't troubleshoot worth a darn. If there is no code then there's no problem - WRONG.

Engines are still basically the same design as that of the Model A (sorry Dodge but needed an example). Is the engine mechanically sound? Are there any vacuum leaks? How's the ignition system? Fuel system? Only when those have been checked can move onto the electronics. The worst part of this is that there are tools available to the mechanic at a dealer, he should be able to see the live data, and determine what's going on.

It's one thing if they narrow it down and it becomes cost prohibitive to repair, it's another not to find it at all.

 

Why are you taking it to the STEALERship??

There are several good threads with pics on this site that tell you exactly how to remove and clean the throttle body. Do this and if the problem still persists then replace the TPS (Throttle Position Sensor).

I've been there done that on the small revs...replaced the TPS and all was golden!

 

the throttle position sensor is one thing they havent changed. but they said they cleaned out the throttle body. i was thinking about changing plugs or even the cat. i really dont know about dodges, older fords 75 to 88. there easy. all these sensors computers are hard to know what could be wrong. thats why i take it to the dealers. thought they would know way more then i