after going into closed loop. 89 TPI.

Car idles normally until it warms up enough to go into closed loop. I searched and found little info. Thx

Bill E.

 

The short answer to your question is yes. If the O2 is bad and reading lean all the time the ECM will richen the A/F mixture, causing a rich condition, in turn causing a rough idle. If the sensor has'nt been replaced in a while, go ahead and replace it.

 

Even with no codes ?

 

If the sensor is still putting out a mV signal a code won't be thrown for the O2 sensor. I'm not sure what triggers the ECM to throw a lean or rich code though.

 

Thx

 

from my understanding the o2 doesn't work all that well at idle speeds so at idle itself more or less it gets ignored until you apply a little throttle. at least with most every car I have seen it's about right. just like the O2 also gets ignored more often then not at WOT.

if you don't mind just out of curiousity is there a chance to disconnect the O2 while your car is warming up see if it runs ok afterwords.

I'm fairly sure it would still run ok but honestly I'm not 100%