camarors8992
NAXJA Forum User
- Location
- Liverpool, New York
My 95 jeep cherokee is lighting up the CEL. We just replaced the old motor with a different motor out of a 94 and now im getting code, 12,21, and 51. I know the cause of 12 and It will just take some time for that to go away but 21 and 51 are both related to the oxygen sensor. The sensor is the original one that was in my 95 with the old engine and it did not throw any codes.
21 - Neither rich nor lean condition detected from the oxygen sensor input.
or
Oxygen sensor input voltage maintained above the normal operating range.
51- Oxygen sensor signal input indicates lean air/fuel ratio condition during engine operation.
12- Direct battery input to PCM was disconnected within the last 50 key-on cycles.
What would cause my o2 to run above the normal operating range ? Why all of a sudden is it running lean ? Any help would be great!
21 - Neither rich nor lean condition detected from the oxygen sensor input.
or
Oxygen sensor input voltage maintained above the normal operating range.
51- Oxygen sensor signal input indicates lean air/fuel ratio condition during engine operation.
12- Direct battery input to PCM was disconnected within the last 50 key-on cycles.
What would cause my o2 to run above the normal operating range ? Why all of a sudden is it running lean ? Any help would be great!