Check Engine, Restricted Performance
 

Well I hate to start off my first Jaguar ownership like this but:


I was met at the airport by the dealer salesman and we drove back to the dealership on the interstate about 25 miles. I bought the car and drove to the hotel. No issues at all.


The next morning I started the 500 mile trip home which is all interstate driving. after about 20 minutes with the cruise on at 70mph I get a check engine light with a "restricted performance" message. There was no difference in the way the car ran at all, which BTW was like a dream. After about 1 minute the message went away but the check engine light always remained.


During the remainder of the trip home the car ran perfect in all conditions, about once a hour the message would return for a minute or so and then go away. Also once again the car ran perfect all the way.


The next morning I did a search for this and got all kinds of hits for all kinds of conditions.


I hooked up my code reader and got two codes (which I didn't write the numbers down) they were 1. bank one lean, and 2. bank two lean.


I took the air filter out and the MAF sensor and the duct to the throttle body off. The MAF sensor wire was clean (looking), there was no issue with the ducting, and the air filter (paper) is practically new. I looked in the throttle body and there is a very slight amount of residue which I just wiped out for now.


My plan for today is to replace the fuel filter and then just drive the car as normal and see what happens.


If anybody has any suggestions they are welcome.


This car has 37,000 miles and seems practically like new all around.


One thing is that the dealer "detailed" the engine compartment with that shiny stuff they spray everywhere ( I hate that stuff). At any rate I'm not sure about doing any washing in the engine compartment at this point until I get a better feel for this light/message issue.


Thanks in advance

Welcome to the forum, you will find much advice and information here. I suggest you spend some time in the DIY thread sticky to familiarize yourself with issues we've seen and discussed.
As far as you current issue, reread the codes and post them here, Lean in both banks means you probably have a vacuum leak on the intake somewhere.
But keep in mind Jag OBDII codes are specific and don't always track with general OBDII, There's a link in DIY to find the Jag specific ones.

Welcome to the forum Mark,

If your XK8 had been standing on the sales lot for a while (anything more than a couple of weeks), the battery could be down. These vehicles are very sensitive to battery condition and throw up all kinds of errors if it's not kept fully charged.

I suggest having the codes read and then cleared. See if the CEL / Restricted performance issue comes back after two drive cycles. If not, then it was just lack of use. If it does, post the codes back here for a decode and possible causes.

Graham

First check the battery under a load test to see if it is part of the problem. I would then use throttle body cleaner and spray around the engine vacuum hoses for leaks as the engine is running. If a leak is detected the engine will begin to stumble then you can begin to pinpoint the problem. Give that a try and see what takes place.

I'll load test the battery. The car was only at this dealer for 3 days, but he got it from a wholesale dealer so it could have sat there. I did run it for about 9 hours on Friday, so the battery should have been charged fully by now, but a load test is the way to go. In the mean time the fuel filter is changed today.


I did look over the hoses/lines yesterday but will run over them again. I'll put a volt meter on it today and see what the charging system is up to. The meter in the car seems to sit at 13 volts no matter what is going on. I think it's just there to fill the third hole.


Thanks for the input.

Might not be the same issue but after pushing my xkr on the motorway I got a ‘restricted performance’ light followed by an amber engine light. The diagnosis from the workshop was that the engine was struggling and due to not using premium unleaded. It’s true i’ve been sipping on the last few tanks, mainly because I wasn’t sure of the performance difference, now I know, it more about caring and providing for the engine. They suggested using the premium unleaded every 4 or 5 tankfuls to keep it happy but I’ll probably resort to every tank now.

I would ONLY use premium gas. This car has not been driven much AT ALL. If the battery is low, change it and drive the car. Seems like we a seeing several folks coming here with low mile cars having issues. Remember folks reading this, low miles does not equal no issues when it comes to a jag.
You issue most likely is simple, stay after it, you will get it. Once you do DRIVE IT>

I had one the performance restriction while i was driving quite fast, the car slow down to 80 90 kmh .. luckely I have always the ODB2 plug and Torque App in my phone, I stop the car plugged the ODB2 and i check the ECU with the torque app, in a few seconds the default was something like air intake % something, idid a reset, and all gone never happened since .
I recommend anyone to have an ODB2 Bluetooth in your car it is very cheap in amazon or ebay, and the torque app it is for free.

one of the other works perfectly with torque app on your phone.

https://cimg5.ibsrv.net/gimg/www.jag...ba76a247ad.jpg

I also have a Cadillac besides this Jag and if I even get close to the fuel tank with less than a premium fuel, i will get a check engine light within 10 minutes. Skimping on the extra cents per gallon will only give you a headache. The difference in performance, the check light, and the reduced mpg is quickly evident with the Caddy. Its a 97 D.Elegance and only allows to be pampered. Amazing what a couple points in Octane will do.