Big Al

iTrader: (1)

Have long tube Pacesetters. If I start the engine from dead cold and just let it idle the O2 sensors read rich, and just stay there. If I bring the RPM up to about 2500 and hold it there for a few seconds the O2 sensor voltages start toggling as I would expect them to. It I then let it idle they keep toggling.

BTW: When I first start it and as long as I don't rev it up the fuel trims are 128, when I rev it they start bouncing around.

Is this considered normal? What should the fuel trim be or do they jump around at steady rpm?

Al 95 Z28