I changed out the upstream oxygen sensor under the engine, Denso unit.  Very tough to get out; less than 3 years old.   I showed it to a different mechanic today, it is covered with soot, he says that it is probably running too rich.  Is there any remedy for that?  The p130 code has not come back up yet, as it usually takes a while.  Still getting the performance issue, stuttering occasionally when it's warmed up.  Thanks as usual for advice.

Injector leaking?  Hard to start after sitting a few days?  Fuel pressure take a bit to build to restart?

Have you checked the plugs?

No problem starting; will check plugs, but never saw issues with them in the past.

color check for rich cyc.

5 hours ago, ThosL said:

No problem starting; will check plugs, but never saw issues with them in the past.

Break out the old Chiltons with the color section on spark plug reading and you’ll see what Larry means. Easy enough. 

Thanks, I'm thinking that the rings/oil burning issue is affecting sensors.  A friend thinks it may be a sensor connected to when the car warms up as the issue doesn't develop until then and is sporadic.   I've changed fuel filter a year ago, plug wires, pvc unit, 02 sensor, etc..  I'll pull the plugs when it's not raining.

Pulled the plugs, that are in very good shape.   I got the PO420 code, catalyst system efficiency, which leads me to believe the catalytic converter after nearly 3 years is clogged up so will use some cat. converter cleaners.  This is the end of the 02 sensor.

 

 

 

 

 

 

Edited August 12, 20241 yr by ThosL