Chugging after exhaust manifold replacement
 

I just replaced the exhaust manifold on my 1998 Camry 2.2L California Standard. Now it idles rough and chugs at around 60-65 mph. THe mechanic said the O2 sensor can tend to foul when replacing the manifold, is this what is going on? Any help would be appreciated.

Did the problem occur after the manifold change?

Is the replacement manifold the same design as the original?

Was original sensor swapped to the replacement manifold?

Just changing a manifold should not cause issues.

Same design manifold, the old O2 sensor was switched to the new manifold, and the chugging was not present before replacing the manifold.

If the check engine light is on, go back to the mechanic and have them output any trouble codes. The code(s) will be specific as to the problem area.

It could be the sensor is bad, is somehow not connected to the cars wiring, a sensor fuse blow (if sensor is heated) or the mechanic could have screwed up. Have the mechanic check things out and post back.

Issues with this sensor can cause your operational problems.