rough idle

[Gettin-Higher]

okay, so the valve chatter I thought I heard that turned out to be a leaking exhaust manifold ended up being no exhaust manifod gasket at all!!

It seems whoever worked on it last put on a gasket for the intake and used RTV alone for the exhaust manifold. When I pulled them off there was almost nothing left of the RTV. I put on the correct combo gasket and things sound excellent now.

The only issue is a rough idle. I've put in new plugs (bosch platinum) New rotor and cap (with brass) and new cables. I cleaned the TBI and it has tons of power and runs great, but has a rough idle.

I sent the serial to Chrysler and they say it still has two recalls that have not been done. Brake lines and Oxygen sensor. Can the O2 sensor cause the rough idle? If not what should I check for?

[Chris S]

Yes, O2 sensor is a common cause of rough idle. The sensor is telling the computer to keep reducing the amount of gas going in at idle until the level in the exhust meets specs. Problem is, if the O2 sensor is shot it will confuse the hell out of the computer, which will keep reducing the gas until the engine barely runs.

[Gettin-Higher]

sounds like it's time for a trip to the dealer.. since it's free....

[CU4WHLN]

The other thing to look for is an intake leak. It's pretty common to get one when replacing the intake manifold.

And I agree... the O2 can and will screw up the idle as the computer tries to figure out what to do

[ELK]

Can anyone explain this.
93 YJ 6 cylinder idled very smooth (much smoother than my 97 XJ). I replaced the O2 sensor, plugs, cap, rotor and now it idles rough. Power is not noticable changed, but the mileage is about 2 MPG better. I'll gladly keep the idle if the mileage stays up, but I can't figure out why it got worse.