2002 Jeep TJ 02 sensor

222MACK

MEMBER
2002 JEEP WRANGLER TJ
6 CYL
4WD
MANUAL
97,000 MILES

My engine light came on, so I decided to purchase a OBD2 reader. The code that was given pointed to a heat shield failure with the O2 sensor. Is there a way to determine which sensor this points to. (Either before or after the catalytic converter)? If not, is there a way to isolate the problem to determine which one has failed?

3 Replies

MATHIASO

MECHANIC
1,209 POSTS

Hello 222mack
welcome to 2carpros.

What is the code?

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Sunday, April 11th, 2010 AT 10:11 AM

222MACK

MEMBER
2 POSTS

The codes are

P0155
P0131

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Sunday, April 11th, 2010 AT 4:04 PM

MATHIASO

MECHANIC
1,209 POSTS

Hello 222mack

P0155 is about the bank 2 sensor1 wiring circuit.
There is problem there. The nature of the problem is a short, or open or high resistance that include internal short or open in the heater element of the sensor or the connector.
Which one?
The bank 2 sensor 1 is the the first oxygen sensor on the OPPOSITE SIDE of the cylinder #1 location.

P0131 is about bank1 sensor 1.
This is the first sensor on the SAME side where the # 1 cylinder is located.
I believe replacing the sensors won't solve the problem, it is least likely that 2 sensors magically died same time. Both sensors indicate low voltage and
low voltage mean lean condition and lean condition is caused by vacuum leak or fuel delivery issue.
Check intake vacuum at idle, and inspect vacuum hose connections. If okay, check for a leaky exhaust manifold gasket. If the vacuum is good, look for fuel delivery problem.

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Sunday, April 11th, 2010 AT 9:44 PM