My truck idled rough only when in drive and stopped when it's in park it barely does it but it's pretty rough idling. Any ideas? I have a tuner if I change the idle Rpms would that help? Thanks

 

I would probably try to figure out why it started idling rough first before raising the idle up. How long since fuel filter change? MAF cleaning, maybe tune up?

 

So... how does it idle at green lights?

Seriously though, what's your idle speed? Any difference between the setting and observed? Transmission fluid good?

 

How many miles? Engine? Last tune up?

 

Wondering what transmission fluid level has to do with Idle speed ?

 

nada

 

First thing that comes to mind is plugs. They can have some miss fires and still not toss a code.

You need someone with a quality scan tool to look at the live data and determine why you have a miss and where. Rough idle is a high likelihood of a miss.

Don't just start tossing parts at it. Diagnose and then repair correctly the first time. An hour of diagnostic time with a GOOD mechanic is well worth the money. You will save that in parts and time.

 

This happened to me. Turned out to be my phasers and VCT selnoids.

 

hey bud, check your air intake and air filter.. mine was super dirty and my intake was full of leaves.. fixed it right up.