Schedule to fly out to pick up an EM1 today

Anyone fix CEL P0172 Too Rich

Seller Cleared the CEL by putting in

JDM P30 OBD-1 ECU with Jumper Harness

Runs Smooth no CEL

Did some research and could be a few things, O2 Sensor is a common issue


Below is some information i found.


Any help is appreciated esp before i fly out 😂

“Problem is, P0172 is a rich code.
Long term fuel trim had to exceed -16% (0.84) to set P0172.

Those engines had issues with the primary sensor going "numb" for periods of time, long enough for the computer to go nuts with fuel delivery but sometimes not long enough to code for a sensor problem.
If the primary O2 gets stuck at a high voltage (rich value), the computer pulls trims down trying to get the desired response from the sensor, but since the sensor is stuck it can't respond. The computer has the ability to add or subtract enough fuel to bog the engine.
Then when the sensor starts working again or the computer defaults to open loop again, the bad running suddenly stops.
THAT'S why I said to unplug the primary sensor and drive it a while first, back in post 3.

Cam timing, tight valves, inaccurate MAP reading, wrong injectors, and more could cause a rich code too”