Joined
·
3,158 Posts
The secondary O2 senser is screwed in the middle of the catalytic converter. Pin 2 is the output and if it stays below .3 volts will set po138. Check the senser for damage. The voltage can be checked with an OBD2 scanner.
There are only two sensers on an 04. Primary is in the exhaust before the converter, secondary as above.
There are only two sensers on an 04. Primary is in the exhaust before the converter, secondary as above.
