ackuric

ok so during closed loop, i think (when its cold) idle is great, but once im in open loop (operating temp) then i get a lil rough idle, and its not constant, its a light quick shake, when it happens its quite consistent, and yes if i push in the gas it doesnt continue.

i noticed on my exhaust, where a o2 sensor is (rear) theres a lot of soot, would that indicate that needs attention? could that be a cause? i dont get any CEL.

as far as the IAC, would a cold idle be effected by it as well as warm? or do you bypass the iac until operating temps.

ackuric

and when i say quick i mean rapid, it doesnt come and go quick. i say it happens 40% of the time when i stop.

ironh19

mines been doing the same thing lately and I haven't figured it out yet. I know its not the IAC or TPS because if it was I would have a check engine light. I replaced all my vaccum hoses and replaced my spark plugs and it still acts up.

ackuric

bump

mustang_montana

sounds like a missfire. could be a fouled plug, id check the plugs and then id clean the iac, and if its none of those id just run some seafoam or some equivalant through it. last time i had a missfire, it was o2 sensor related though.