Hey guys! So I got my 2014 XJ-L AWD and a check engine light came on. After scanning it I got p0042 stating "HO@S Heater Control Circuit Bank 1 Sensor 3". I purchased the o2 sensor and replaced the defective sensor, cleared the light and was good for a bit and now 1 day later it has popped up again with the same code. Am I doing something wrong here? Any suggestions? Thanks guys!

 

It may not be the sensor itself but the wiring between the sensor and the computer. If you have a broken wire, it can make contact some times and allow the signal to go through it and other times it will open up and make the computer think that it is not seeing anything. This is where a good inspection of the connector will show any corrosion and then hand over hand the wiring, looking for the wiring to make a sudden direction change. You can even move the wiring a little bit (bending it over a paper towel cardboard center) and see if you see the wiring bend funny that way. Beyond that, now you are into proving that the sensor is outputting the correct voltage and proving parts of the system good to get yourself down to a bad component.

 

Hmm, ok Ill have to take a look.

 

Actually there is a TSB on O2 sensor heater:

 

I took the jag to the dealer and showed them the TSB and $600 later the car is fixed. It turns out another 02 sensor was the culprit even though I was getting the same code. Perhaps their WDS system saw the code in a way that I just couldnt. Anyway, its resolved!

 

Why wouldn't that be a covered repair under the warranty or at the very least emissions warranty? Unless the XJ is more than 5 years old or has over 50.000 miles it is covered by Federal EPA Laws. IMHO

 

Unfortunately it has over 80k on the clock so it wasnt covered