Problem: The vehicle was brought to the shop
because the emissions monitors kept resetting and the engine
Details: Another shop had previously
replaced the rear B1S2 O2 sensor due to an O2 sensor DTC. When it
came in, there were no DTCs stored – active or pending.
Initially, the tech checked all power and grounds to the PCM then
checked the connectors at the CKP, CMP and the PCM. He also
checked connections at the battery and alternator. The
connections were all in good condition.
Next, the tech disconnected the rear B1S2 O2 sensor and
road-tested the vehicle. The engine did not stall. The
Tech-Assist consultant advised that aftermarket O2 sensors –
especially on Chrysler products – often do not work correctly and
can cause problems.
Confirmed Repair: The tech replaced the
aftermarket B1S2 O2 sensor with an OEM sensor. After the
replacing the sensor, the monitors operated normally and the
engine stopping staling – problem fixed!