Is there any way to bypass the oxygen sensor on an 88 3.6L . The sensor looks to be mounted near the entrance to the first cat,so if I removed the cat completely,is there a way for the sensor to be tricked into getting the correct reading?

 

I don't think there would be any simple way to bypass the O2S since the ECM depends on its signal, which fluctuates between about 800 mV and 200 mV, to maintain an AFR as close as possible to a stoichiometric mixture, or Lambda (an air-to-fuel ratio of 14.7:1, or exactly enough air to completely burn all of the fuel).

Have a look at the Oxygen Sensor section on pdf page 53 of the AJ6 Engine Management System Diagnostic Manual, which you can download here:

http://www.jagrepair.com/images/Auto...stem%20S91.pdf

BTW, I think on our '93 there is either one pre-cat in the downpipe before the O2S, or two small ones, one in the downpipe for each bank of 3 cylinders. The EMS manual mentions that the O2S is "located in the exhaust down pipe after the first catalyst...."

Cheers,

Don

 

Hello everyone,
I thought that on the models 1988-1989,
There was no lambda probe?
On my November 1989 model no probe
If I'm not mistaken it concerns the XJ40 from (VIN) 667829 up to 708757?

best regards

 

For many markets around the world, I think you may be correct, but I am fairly confident that in the U.S. all of the XJ40s were equipped with oxygen sensors/lambda probes due to emissions regulations.

Cheers,

Don