This is on a 2004 with very few mods - Stillen air cleaner, lightweight flywheel and Wolf clutch.
Back story - the car was occasionally puking (0 RPM) if I would be hammering it and then got out of the gas. Also had begun idling pretty rough.
I cleaned the Mass Air Flow Sensor with MAF cleaner and the throttle body with carb cleaner.
The idle seemed to stabilize and it hasn't puked on me yet.
However - the idle has now gone high (1200) and doesn't seem to come down as quick when you get out of the gas and clutch in.
CEL is on and throwing a P0507 (P0507 Idle Speed Control System )
I'm guessing I need a new MAF sensor but wanted to see if anyone else had seen this before?
Thanks in advance for any advice.

 

Did you move the butterfly in the TB when you cleaned it? If so, that is a big no-no. And or you might have a defective TB or the position sensor riveted onto the TB, in which case you need a new TB. Reman unit at the dealer cost me around $160 a couple years back.

 

Yes - I definitely opened the TB and used a tooth brush in there.
Why is that a bad thing to do? Not trying to be a jerk - I just don't understand. Doesn't it open with the throttle?

 

The 350 is throttle by wire. Electronic control, not linkage. You are probably going to have to go the dealer and have the TB reprogrammed - it has lost it's idle position, although that is not exactly the technical term for it. Lots of threads on this. Search cleaning TB for starters maybe...

 

Perf - thanks for the info, much appreciated.