crgblues

Any help would be greatly appreciated; I have checked for vacuum leaks and cleaned MAF with MAF sensor cleaner. I have raised the idle rpm setting with my tuner to over 900, but, still the craziest thing; while coming to a stop, the rpms drop to under 500, until I have come to a COMPLETE stop, then, it rev's back up and surges a little bit around 750. It really messes up bad if I have the AC on; sometimes dies. Any ideas? Related upgrades: JLT cold air, Hooker Long-tubes, after-market cat's, o'2's are on... btw, my SCT Flash device gives me an error when trying to read the CEL code. (it comes on when the idle drops, and gives an "idle below threshold" code.)

Thanks!

kcmarti

I had the same issue years ago, my fix was the following:
(1) Remove, clean, dry, and LIGHTLY oil the filter on the CAI.
(2) Clean MAF (again) using MAF cleaner an carefully run a Q-Tip along the MAF wire.
(3) Remove CAI elbow and thoroughly clean the throttle baody and plates (I used Q-Tips and a lint free rag to get all the gunk off of the TB and plates).
(4) Put everything back together and re-load your favorite tune.

05 Mustang

my 05 did the exact same thing. I tried cleaning the throttle body (was very dirty) & MAF sensor like everyone on here suggested, but it didn't help. As a last resort, I ended up replacing the throttle body. That fixed everything.

crgblues

Wow; what a relief to know I am not the only one having this problem! Thanks for the help!

05 Mustang

lol, yeah it definitely scared me the heck out of me first time it happened because I had never had any problems with my car up to that point, then all of a sudden for it to act up...I guess it's one of those things that if you maintain you'll be just fine, but if you don't, it'll catch up with you??

good luck with yours!

crgblues

What threw me off is that it started acting up shortly after installing my cold air intake and retuning it. That lead me in so many different directions, thinking it was the tune, filter, MAF, or a combination of the headers and that particular cold air not working together, and the throttle body wasn't even THAT dirty. It's back to running so great, I can't quit driving it!

Simon1

It's probably tune related. Email your tuner and you shold be bale to work with him to fix the driveability issues you are having.

brayson

I had some rough idle issues that were resolved by cleaning the throttle body. It seems once the CAI loses its oil, more dirt can get through and leads to a very rough idle. You've already cleaned the MAF, so I would suggest TB.