Engine Light

JEEPHELP2003

MEMBER
2003 JEEP LIBERTY
3.7L
V6
4WD
AUTOMATIC
100,000 MILES

The engine light keeps coming on even after having 2 oxygen sensors replaced. One of the sensors was slightly melted so we thought we found the problem. The 2 that were replaced were the ones indicted by the "bank 2" location. However, the engine light came right back on. The code is P0432, Cat bank 2 sensor. Could you please give me a direction to go so my vehicle engine light can stay off? Thank you!

Tuesday, August 30th, 2016 AT 3:55 PM

1 Reply

CARADIODOC

MECHANIC
34,330 POSTS

P0432 Main Catalyst Efficiency Below Threshold (Bank 2)

Diagnostic fault codes never say to replace parts or that one is bad. This is a perfect example. The code means the catalytic converter is not doing its job, and you need two properly-working oxygen sensors to determine that. The sensors you replaced were doing exactly what they were supposed to do. That is to report the amount of unburned oxygen in the exhaust.

Typically your mechanic will induce a forced rich condition, then a forced lean condition, and watch the sensor data on a scanner to see how the oxygen sensors respond. Once they're verified as working properly, the solution will be to replace the catalytic converter.

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Tuesday, August 30th, 2016 AT 8:34 PM