Just had exactly the same problem with my 2012 XKR...also could see fuel dripping over passenger exhaust pipe...had it towed to garage and now waiting for diagnostics 😜

 

Cost me about two grand, and then I had a couple other things added in there also, like trans fluid, spark plugs and a few other minor items.

 

2007 XKR experiencing the same thing. Heavy acceleration, then suddenly winds down, Restricted Performance.

1. Replaced spark plugs based on engine code.
2. Next code was vacuum leak - replaced gasket connecting air intakes.
3. Garage said no codes, I picked it up, didn't even hit 50 mph before the engine sputtered and Restricted Performance.

Appreciate the other items to check. Taking it back to garage Friday to read new codes. Will check the battery and see if they can diagnose the intercooler and check the exhaust.
Also from re-reading I ought to have the injectors checked as well.

Thanks to all posting - these forums can be a life saver - and a wallet protector.

 

There's really not enough provided information.
So if I hazard a guess... '07, XKR, hits 50, then sputters.... clogged CATS?

 

Would be my #1, too.

 

Please pardon my ignorance - what are CATS ?

Are they part of the fuel injection system ?

 

Catalytic Converters.
Exhaust system.