I have a stock 4.0l 1991 xj which is NOT in the USA. I am in Abu Dhabi and I have restored this 91 back to her wonderful self, and I am planning on shipping this XJ back to Texas with me when I leave here. it was made for export but everything has been replaced that made it an export model. I have NO o2 sensor, I have a plug in the exhaust pipe where the sensor should be and a plug hanging loose under the charcoal canister I assume is for the o2 sensor. I assume something has been done to it so it won't throw a CEL when the o2 is not there. is there anything I should do to fix the bypass ? I have no idea where it was bypassed at. I want to add the 02 sensor and make it all ready to ship home. any ideas ? it runs great without it, but if it is supposed to be there I want to add it. I could just stick one in there and hook it up but it won't be functioning, it just looks like it is...I want to know where the bypass is done so I can UN-bypass it. any help would be great. thanks in advance.