wcaswell wrote:
Update #2. Replaced the Throttle Body. The engine now has throttle! Codes cleared. Now getting codes 2195, 2197 which indicate a bad passenger side O2 sensor forward of the Catalytic Converter. Replaced it, cycled the PCM, but still getting those two codes and rough idle and low power. It's drivable. We'll put some miles on it this weekend and see how it goes, then into the shop. Could be a vacuum issue.
Check the PCV line for cracks, that is a typical problem on the Modular engines, plastic gets brittle and breaks.
While you are at it, go ahead and change the driver side front O2 sensor, it is most likely not far behind in failing.
The front or upstream O2 sensors are the ones that the ECU uses to monitor and adjust the fuel mixture and are critical for correct engine operation..
The rear or Downstream O2 sensors are mainly for monitoring the efficiency level of the Cats (IE for emissions purposes) and are not critical.
