Bad idle

[Markviiiedrea]

I replaced my entire drive line recently and while the tranny was out I replaced my IAC the car still has a rough idle. I have a new mass air a cold air box and K&N. the intake tube is modified (deleted silencer and resonator) the only think left that I can think of is my O2 sensors because I still have the sulfur smell from my cats and now with the 4.10s my gas mileage is really bad some where like 10 miles to the gallon if I'm nice. Would my stall have any thing to do with it? It’s a 2800 9" from Midwest converters

The car is a 94 mark.


P.S. where and how much can I get a Speedo gear to correct for the 4.10s

 

[JoeyLincolnMK8]

have you check the idle pully?

 

[Dominus]

Coils, injectors. Check both.

 

[MonsterMark]

Probably a coil. (just a guess)

 

[chicken]

how rough of an idle? mine had a slight "bobble" here and there and the o2 helped it out a little, and the sulfer would mean you are running rich, that smell is you cookin your cats which could also be caused by "slow" o2's

 

[Markviiiedrea]

all mentioned above are new(except the injectors), i bought new plugs and some sea foam so when the o2s get here i can sea foam it and change every thing afterwards. think it will help?