I own a 2001 Jaguar XKR Convertible, 4.0L supercharged. VIN: SAJDA42B21PA13401. It is my fourth Jaguar.

The check engine light is on. I took the car to my local dealer. They diagnosed the fault as P1647 ... upper oxygen sensor driver's side (US car). The sensor was replaced. The fault continues. Frustrated, I took the car to my local mechanic. He verified the fault as P1647, upper oxygen sensor driver's side. He replaced the sensor. The fault continues. The part used each time is LNE1684BB, which is the OEM part.

I have tried to isolate this check engine light on my own. As a result, I have reproduced the fault, and recorded an absolutely REPEATABLE set of steps. This information was sent to Jaguar Coventry, who tossed the inquiry back over the pond to you.

The steps:

Engine off. Insert Car Diagnostic Scanner Tool. Turn ignition to ON, did not start the car.

After verifying protocols, tool reads P1647 fault.

Reset the fault.

Turn ignition OFF. Remove tool.

Drive car. Doesn't matter if it is highway, local, 5 minutes, or 2 hours. No check engine light appears.

Stop engine.

Dealer thought the problem was fixed. Dealer was wrong.

Restart car. Within 10 seconds, check engine light appears. Driving car does not reset light. Again, doesn't matter what drive pattern is used.

Repeat process with Car Diagnostic Scanner Tool. (Diagnose fault as P1647, reset fault, remove tool.)

Drive car. Check engine light remains off.

When car is restarted, whether 5 minutes or 2 days later, check engine light appears.

Pattern is 100% repeatable.

Initial use following reset with tool is successful. Next engine start ALWAYS FAILS.

Replacing upper oxygen sensor with OEM part does not change the pattern. Replacements was $650 cost at dealer, and $450 with my local mechanic.

Contacted Jaguar Coventry. They forwarded this letter to Jaguar North America. I again asked them to please review my inquiry. The dealer was useless. My local mechanic achieved the same result. Jaguar Customer Relationship Center Representative (I will withhold name) said go to authorized Dealer. Obviously, the representative did not read my information. I again sent the message. Received same response with additional: dealers have technical team to diagnose and support you. It was the technical team that already failed the diagnosis and charged me plenty for their efforts.

This is not a sensor issue.

Anyone out there have experience with resetting P1647 error codes. The Jaguar dealer is useless.