i had os 2 sensor errors changed them all and the fuse that controls the heater part, check engine light went away i dont smell unburned gas any more but i still get restricted preformance ! i have a low coolant light which is the sensor so i dont think that has anything to do with it any suggestions?

 

can you read the codes and repost? Kinda taking a wild *** guess w/o them unfortunately.

 

I had this on my 2000 XJ, What cured the problem was a new partload breather, MAF cleaning, Throttle body cleaning, spark plug change. Wasnt sure which one corrected it, but cost to do all that was just $50 for parts.

a few months later 1 gear went on the transmission, definately get the codes read and look into it from there. Could be a host of issues, could be something tiny.

 

thats what weird! i get restricted preforamce but NO CHECK ENGINE LIGHT any ideas?

 

Been there done that! Use this link http://www.gusglikas.com/AutoRepairR...erformance.htm to my page and you will see what I had. Do as suggested clean the MAFS, Part-load breather and the throttle body. When you work on that you need to look at your hose from the MAFS to the Throttle Body and see that you do not have any cracks. If you do you will need to fix or replace it. Look at the one on my page http://www.gusglikas.com/AutoRepairA...HoseRepair.htm

 

what the MAFS, Part-load breather? looking at your site now this problem has been driving me crazy!

 

the partload breather is the plastic hose that goes into the valve cover. maf is the mass air flow sensor. its the the air meter right after the air filter box, you need to unscrew that out and spray it wil maf cleaner. look at the diy articles and it should walk you through it.

 

Thread in the General Tech Help section from the last couple of days should help, and has links to the DIY articles Strate mentioned:

https://www.jaguarforums.com/forum/s...ad.php?t=31920