Misfire between 2000 and 3000

[docgeebee]

Yes. It runs much better when I first start out and it's cold. It gets terrible when it's warmed up.
You're the first reply that has had a similar problem.
I've got the sensor ordered.
I can't tell you how much your reply means to me. This 'stumble' has been giving me fits.

 

[96LSteg]

Yea se what happens is when the car is cold it bases the air/fuel ratio off of the MAP sensor (I think it's called open loop). Once the motor warms up it bases it off of the o2 sensor (closed loop). If the heating element is bad in the sensor, when hot the car is still in open loop causing a misfire at a certain rpm. I put in a brand new OEM o2 sensor and my problem was solved.

 

[Mendez_89]

did you end up finding a solution to the problem cuz that is currently happening to my 89 integra. ive replaced o2 and cat still does the same thing and the check engine light comes up. but when I turn it off and back on its not there. any suggestions been reading around saying maybe main relay or icm?