It is relatively mild but I am wondering about what the cause could be.
No missfires apparent under load or while driving but If I pay attention to the car's vibrations at idle or when in N or P I can feel a missfire.
I just recently replaced the opti and the bases gaskets are damaged so I had to rebuild the gaskets with "the right stuff".
the only thing I can think is I didn't get the top two opti cap screws tight enough and the rotor is having to arc farther at the top of the cap??

I know.. grasping straws, and why if this was the case would it run better closed loop vs open loop?

Should I be thinking more Mass airflow\o2's?

Has anyone ever found a way to add tension to the top two torx screws WITHOUT REMOVING the h20 PUMP?

Am I going to damage the engine driving it with a slight missfire If I can only detect it at idle??

Any advice about my queries is greatly appriciated.
thanks,
Tal

 

Try disconnecting an O2 and see if it runs better even after it is fully warm. If so, you probably have an O2 related problem. Either O2 or wiring.

Do you have headers? If so I would suspect wiring.

 

I had this same problem, and my was a bad opti. Try to have the code read, and then got to shoebox's website and find out what it is http://shbox.com/1/Dtcs.htm, when I had my problem I was throwing code 36