My 2004 Ram 1500 is idling at 1350 RPM. It has the 4.7, with a K&N Cold air intake also. This is absolutely killing my MPG because even when i let off of the gas and am coasting the RPMS dont go down past this. Im worried that it is a vacuum leak but i cant tell because the CAI is so loud. Im wondering what else will make it idle like this. Any help is appreciated, Thanks

 

Check to see if something is loose and got into your Throttle cable and cam. Maybe it's being held by something...

 

Are you coasting when its at 1350rpm or are you at a stand still? I know you said coasting "with foot off the gas" in your post, which would mean you aren't 'idle' or even 'idling' so the 1350RPM is normal. If you are putting it in neutral and letting your foot off the gas while either rolling or at a dead stop and its still up that high then there could be something holding it stuck open

 

Clean your TB start simple. Any Codes??

 

Vacuum leak is most likely...

With the truck idling, Spray Brake Cleaner on the vacuum lines, when the engine goes to stall you've found your leak.

Just keep the spray away from sensors and electrical and you're good.

 

did it start after the k-n filter install? if so double check all your connectors make sure they are tight. I agree sounds like a vaccum leak.

 

its had the k&n on it for like 6 years. i was leaning towards vacuum leak but checked them and couldnt find one. its throwing an excessive idle code, thats the only one? when i say idle i mean sitting at a red light with it in gear, its always idled at 1200 but now its up in the 1400rpm range.

 

Take the airbox off and see if something is stuck in the butterfly. Sounds like the throttle is being held open by something... That or a vacuum leak...

 

What have you done to have the idle normally at 1200?

 

Yeah idiling at 1200 is off