check engine light goes on and off

[montysbxj]

i haev a 2000 xj with the 4.0 and i recently put a 3.5 re lift on it. i was playing in some minor mud and climbing some small dirt hills and making sure that 4 low worked since i just bought it. i was going up the hill to go out still locked in 4 low going really slow and the check engine light came on. i got it to a scanner that nigth and it had a po138 code. i drove it for a day with the light on and then it went off. now when i am at the same place going up the same hill in 2 or 4 wheel the ligth comes on and then goes off an hour or so later and comes on spiratically other wise and then goes off. any help is appreciated thanks again

 

[XJ99]

P0138 HO2S Circuit High Voltage Bank 1 Sensor 2

dont know what It means but thats your code pal

 

[mgt]

Do all the gauges go dead when the light comes on ?

 

[comancheon33]

Bank 1 sensor 2 code means your O2 sensor after the converter is prolly going bad. Replace the o2 sensor. Voltage to means the sensor is not doing its job. The sensor is sending the ECM a full 5 volt reference signal. Which means it is taking a reading from the exhaust. Plus the rear sensor has a built in heater element in it.

 

[montysbxj]

the gauges do stay on. the light is back on on the dash and it hasnt gone off yet. so i may take it in and have it checked but i dunno