hey guys does anyone have a idea what makes my engine light stay on and the restricted performance amber light on and off most of the time on my 2000 jaguar xj8 . i got codes P1111, P0174, P0171 but i bought a new MAF sensor new spark plugs and even replaced the gasket seals around the plugs that were leaking oil into the plug hole but lights are still on . the car runs great still i don't notice any performance change .. does anyone have an idea ?

 

Welcome to the forum.

You should stop by our New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and introduce yourself to everyone.

P0171 & P0174 is for lean on both banks. Usual cause is a vacuum leak somewhere after the MAF. Lots & lots & lots of posts here on the forum about this. Rubber vacuum hoses do perish with age, could be a split hose or maybe even one has popped off.

Also, the plastic intake tube between the MAF and the throttle body has been known to split at the seams.

 

thanks for the advice ill check it out

 

Did you get this sorted?

 

nope not yet i bought a aftermarket mass air flow sensor off eBay but still no luck but a jag machanic told me that the aftermarket sensor are not good that i should buy the original one so now i waiting till i get the money but my car still runs fine i can do 70 =80 mph on highway and no change so im just waiting for now

 

While you're waiting, go ahead and take of that intake elbow and all the ancillary tubing. Inspect all of the tubes for cracks and holes and check all mating surfaces.

I recently had a severe shifting issue that one dealer said would require a new transmission and another said would require a new throttle body...turned out to be a pebble stuck under the clamp on the airbox side of the intake elbow. It is incredible how small of an air leak can cause serious problems.

 

Check the Part Load and Full Load breather tubes CAREFULLY!

 

this might be a dumb question but what part is that ? is it the air intake tube that goes from the throttle body to the air filter box?

 

Looking at the engine bay from the cabin :

Full load breather hose : plastic tube going from the main air intake tube (air filter box to throttle body) into the right hand valve cover.

Part load breather hose : smaller tube connecting into the inner side of left hand valve cover near the front.

Both have "quick connect" fittings, take care if/when removing these, especially the part load hose. Do not lean on the plastic coolant lines running across the top on the LH cover, they will break quite easily. Ask how I know this ....

AndyP

 

I had a severe shifting issue when hitting the gas hard on the highway to pass another car -- I figured my transmission was on its way out. I had what seemed like an unrelated issue which would crop up as a Restricted Performance message and poor (but not so bad) engine performance. I inspected everything under the hood and noticed the clamp around the large hose coming from the airbox was loose -- after tightening it I noticed an increase in engine performance, no more restricted performance message, and .... I've noticed that the severe shifting issue has gone away! Until I read this thread, I never even thought that maybe the shifting issue was related to the loose clamp!

It truly is incredible! Thanks for your post.

Mike