I have a 2001 XK8 convertible and had two recent instances of restricted performance. I read the following sequence of diagnostic codes: P0303; P1316; P0353; and finally P1111 (normal). The restricted performance indicator went on both times and a yellow bar appeared above the indicator and has come on intermittently two times. I have approximately 82,300 miles on the car and just had a 90,000 mile check-up. Any ideas of what the cause(s) might be and what steps I should take to correct them? Thanks. I just want to have some confidence that I can take this car on small trips without being towed somewhere.

 

I've had a similar issue, check out my quest to solve it here: https://www.jaguarforums.com/forum/x...g-codes-70681/

My car will run fine 99.8% of the time. When it is hot and sits for a bit, and then is run, it will start a touch rough, smooth out, throw the Restricted Performance, then be back to normal. The codes are indicating a misfire and it seems to probably be due to something in the fuel system. I ran some BG-44K through and it didn't take care of it. Next up is the fuel filter for me, since it probably needs to be changed anyway.

 

K. Westra,

thanks for the wealth of information and research. I will try to follow your path to success.

 

The code reader agreed with my mechanics diagnosis. The number 3 coil when it got hot caused the engine to misfire. Solution: replaced the number 3 coil and the cat is purring again. Thanks for all your suggestions.

 

Just experienced this today on my 2000 XKR 99,600 miles. There seem to be a number of issues than can cause this but the one I see mentioned that hits home is fuel. I just filled the car with premium this week and haven't driven it more than 20 miles. I have had problems with the check engine light on my wife's ES300 using midgrade and it seems also related to where she buys gas.
Wondering about how closely fuel octane and quality are really monitored. Also live in Wisconsin where fuel, especially at Citgo stations uses ethanol in all grades. Any thoughts from our experts?

 

I have wondered the same. I have occasionally gotten either bank 1 / 2 running lean / rich codes. They seem to go away by the next fill up (although I normally do clean the MAF and put a bottle of Techron in the gas tank which is a fuel injection cleaner). I have often wondered is it from a lower quality gas, winterized gas formulation in Maryland, higher Ethanol content, or some other type of gas related issue.

 

Same problem. Had an air leak mixing in an elbow under manifold. Took light off. I think this idiot light is a way to make Jag owners nuts. The car runs great. Restricted performance -according to Jag- means the car won't drive more than 20 mph. Some people have said they let the car sit a few days and the light goes out. I wish I could just disconnect it.

 

Jaguar and Audi are two examples where "over engineering" has be allowed to transcend the build quality and reliability of vehicles. The "KISS" philosophy is still superior to most of what is happening in the automotive world. Far too much creative license has be put upon the car buying public. Owners being used to test ideas and are putting engineer's and technician's kids through college at an alarming rate.

 

Dumped a can of Seafoam in the tank and blew the carbon out on some back roads. Live 2 miles from Road America. Running fine for now. Not sure you can just let these things sit around all winter and expect them to run well. They have to be driven. BTW, I know therew are lots of opinions but Seaform has cured alot of ills for me over the years. Has anyone used the Seafoam induction cleaning setup on a Jag? Noticed some have just stuck a line in a container and sucked it out, but this seems purpose built.