Restricted performance

[royalbluemersey]

Hi, I have a 2004 Super V8. The engine management light is on and 'Restricted performance' shows intermittently. Any suggestions? I am in Islington. can anyone suggest a good independent Jag specialist I could use? Thanks, Mike

[ptjs1]

Mike,

It COULD be something quite simple - throttle body cleaning, vacuum pipe, lambda sensor etc. Are you in a position to read the fault code that is being thrown - ie do you have a simple cheap OBDII bluetooth plugin you can use? Even if you can't fix it yourself, it would be really helpful for you to know the fault code before getting someone to look at it.

Good luck

Paul

[royalbluemersey]

thanks for the advice Paul. You have said enough for me to know I will need to leave it with a good mechanic. No recommendations for mechanics/garages handy for Islington North London anyone?
cheers,
Mike

[Norbertflyer]

As Paul said, get the error codes read first. Jag dealer will do it, if you don't have a £35 OBD2 code reader. When they're available, post them here if you can't find the interpretation from the interweb. Richard.

[royalbluemersey]

thanks Richard.
I got an obd2 scanner and the check shows the following:
P0172
P0175
P0175 P
P1111 P
Apparently this indicates both banks are running too rich but it sounds like there could be a number of causes.
Still no recommendation for an independent mechanic/garage in North London?

[JimMann]

Hi Mike, in regard to a potential Jag specialist in your area, then the best advice is to talk to your local Region colleagues. You would be amazed at the limited number of folks who actually trawl the Forum and provide answers and it can be difficult for folks to recommend local specialists when they reside quite a way away.

Check the contacts pages of the magazine to get some details of your local regional members and give them a call / email.

Jim Mann

[ptjs1]

Mike,

Ignore the P1111, that's a Systems Test Code.

The key ones are the P1172 & P1175. That would seem to indicate that both banks have been trimmed to max lean but the mixture is still rich.

Whilst there are a number of options, he most common cause of a joint P1172 /5 is the MAF sensor. I'd start by very gently cleaning the MAF sensor, reset the codes, drive the car and see if they return.

Good luck

Paul

[Andy P]

Hi Mike,

Here are the definition and possible causes from the DTC Summaries manual:

P0172

P0175

Sorry I can't recommend anyone in North London but a lot of Jaguar owners on the X308 Facebook Group Page recommend S.E.Jags:
https://sejags.wixsite.com/website
I have not used them myself though but they seem good.
Hope you get it sorted.
Good luck.
Andy

[Norbertflyer]

Cleaning the MAF sensor is one of the easiest maintenance jobs on an x350. Several sources of help on here and videos on www. Best of luck. Richard

[royalbluemersey]

A belated thanks to everyone for your help with this. I have only just got around to addressing it. My mechanic didn't think it was running rich so hopefully it was the MAF sensor. He has cleaned it and the engine management light is off-for now.
Let's see how it goes.
Mike

[ptjs1]

Good result Mike,

X350s are very sensitive to throwing codes because of the MAF sensor. Mine did it once a month, as I crested a particular hill on the M20 and came off the throttle. I never did understand why.

Maybe invest in a cheap £4 obdii dongle and a £4 obdii phone app and you can just read and reset the codes next time it happens.

Cheers

Paul

[royalbluemersey]

It was fine for about 80m but the lights have come back-sigh. does this suggest the sensor is in fact the problem?
if so, I am looking for a replacement on ebay but I can't tell which numbers on the part are essential for the part serial number.
mine says 1x43-12B579-AB then VN197 400-3021 then Denso and then 07U01
Mike

[ptjs1]

Mike,

What fault code has it thrown this time?

Paul

[royalbluemersey]

Paul,
it's showing

Fault 01
Pend 02
P0172 01/03
P0172 P 02/03
P1000 P 03/03

Mike