Rough Idle under certain circumstances

[98SVTContour98]

I've had several weeks where I don't get to drive/start my car for a full week. Upon starting the car for the first time (after a week of sitting), the car idles really bad, the entire car is shaking...sometimes it will die, sometimes it will just idle bad. Once the car is re-started (between 1 and 2 more times), the car idles/runs fine.

Additionally, I do get a little hesitation if I go WOT from a roll, where I stomp the gas and the car doesn't immediately go, just throwing that out there in case it's relevant.

The current codes I'm throwing are: p1506, p0420, p0174

 

[98 svt]

For the 1506, I would remove the IAC and clean it out with some carb cleaner.

Do you have an off-road H/X pipe, or do you have cats in your exhaust?

 

[98SVTContour98]

For the 1506, I would remove the IAC and clean it out with some carb cleaner.

ok, thx

Do you have an off-road H/X pipe, or do you have cats in your exhaust?

Off-Road H-pipe

 

[98 svt]

ok, thx



Off-Road H-pipe

Have you had the rear O2 sensors shut off in a tune? Do you have a functioning pair of MIL eliminators?
The H pipe is most likely the culprit of the other 2 CEL codes.

 

[98SVTContour98]

Any idea on the bad idle? thx

Have you had the rear O2 sensors shut off in a tune?

I'll check

Do you have a functioning pair of MIL eliminators?

I thought I did

The H pipe is most likely the culprit of the other 2 CEL codes.

ok

 

[98 svt]

Any idea on the bad idle? thx



I'll check



I thought I did



ok

Did you clean the IAC valve yet? That may help with your idle.

 

[98SVTContour98]

Did you clean the IAC valve yet? That may help with your idle.

IAC valve was spotless (it's not quite a year old)...however the part of the intake manifold it attaches too is pretty gunked up...barely ran my finger in there and it came out dark black and sticky (see pic below)

 

[98SVTContour98]