An obscure question but if there is an answer it will probably be here!

Can an underfloor cat exhaust section from a standard XJ6 (part no NNA6752CB) be fitted to an XJR with manual gearbox? Jag list different part numbers for auto and manual, aftermarket cat suppliers only seem to have one part number (for each of the cup or sleeve fittings. XJEngineer thinks that the auto requires the correct part to clear the transmission but that a standard XJ part should fit. Can anyone confirm or deny this?

Thanks, Chris

 

Sorry, I can't answer the exact question you asked, but I will try to provide some useful info that may help you solve your problem.

The underfloor cats are not monitored by the oxygen sensor. Only the cats in the downpipe are. Consequently, even if you were to remove the underfloor cats and replace them with a straight pipe or a resonator your car will continue running fine. It may even pass emissions, given the age. Any aftermarket weld-in catalytic converter that is of the same type as original and physically fits will work. Not sure how it works in your neck of the woods, but over here we just weld in cheap aftermarket replacements. They are like $30 a piece plus $50-$100 in labor to weld them in.