I could use some help. I have a 2000 XJR with the check engine light always on. The dealer said it was a bad O2 and would cost 1,100 to repalce it. I told them no thanks so they cleared my computer of codes and I took it to a tech I trust. He said I show a factory code 1647 and most of my "ready
Monitors" were not turned on. I told him I have put 300 plus miles on it since the dealer cleared codes which seems to have him stumped. He said I need to take it to someone who knows Jaguars. I'm north of Houston, and I'm clueless. Any ideas? Thanks

 

As far as I can tell, code P1647 is for the O2 sensor, B bank, upstream. Here's what my chart says:

P1647 ECM HO2S control malfunction –
B bank, upstream
Ignition ON > 8 seconds Y 2 N When CK ENG MIL is activated
(DTC flagged; second trip), ECM:
– Inhibits B bank upstream HO2S
operation

Possible Causes:
HO2S heater failure
HO2S sensing circuit short circuit to
ground or high voltage
HO2S sensing circuit open circuit
ECM failure

I've always been a great believer in taking a Jag (or any complicated auto, be it Jag, BMW, Benz, whatever) to someone who specializes in that brand, and I gather that's what your trusted tech friend is telling you. But having said that, I'd call some Jag independents for some quotes...on an 8 year old car, you'll get a RANGE of quotes, and almost all will be cheaper than a dealer.

Good Luck!
Greg
'04 XJ8

 

A bad 02 what? If they are talking about a bad 02 sensor, I'd run far and fast from that dealer.