I seem to have been posting in the wrong forum. I have been chasing error codes in my xj8 for a week. I am now down to an O2 failure. Switching the O2 connector plugs at the firewall moves the error to the other bank. My problem is finding a store that can get me one. It also seems that they will cost $300. I have read the Jag " S " O2 sensor will work but sometimes in the pics it shows a round plug and sometimes a grey square plug. I need a square plug. Can anyone help me on this?

 

You might want to contact Jagbits a Forum sponsor as you can see from the attachment they are well below the $300.00.

 

If you are talking about the upstream (upper) oxygen sensors then the following worked great in my X308.


Mine is an XJR, but I think they use the same oxygen sensor.

 

Depending on the year and how many sensors your car has, universal Bosch ones would do. I have only Bosch u iversals in and the Lambda numbers are perfect. Though it runs really rich when you floor it

 

A friend gave me an old o2 sensor and it works great. At first it was missing but I read up on the forum that the spark gap should be around 38. I had them gapped to 50. Regapped them and the engine runs and no more error codes. How ever it does not want to idle well. It is around 500 rpm. If i push the throttle till the rpm is about 800 it runs and accelerates great. Bad hesitation between 500 and 800 rpm. Can I adjust the idle speed?

Do you have a part number for the Bosh sensors. I am using Bosh iradium spark plugs. has anyone had experience with those?

 

No major identifying codes now but I get random misfires. Sometimes it will tell my what cylinders and some times it will tell me different cylinders and sometimes just random misfire. It is not being user friendly or consistent. Going for a long ride now to run it a bit.

 

Ran 5 miles and had to go home, running horrible missfires all around.

 

Have you actually checked the O2 sensors are transmitting signals? Not that they are dead. As one of mine was nearly dead, the car would randomly misfire...

 

I fixed it. It was a bad tank of gas. Not even a gas treatment would help it. I was down to half a tank and filled it with the best premium I could get and within a mile it was running beautifully. I can't remember the car running this good. All the little codes are gone and the world is a happy place again.

 

glad you were able to fix