Hello Everyone, As you might recall a couple months ago, I'v replaced my Air Filter and just recently I personally cleaned out the Throttle Body and MAFS plus the Air Intake with CNC products. It appeared to really do good, as I noticed improvement in acceleration and the CEL and RP went off for good.. But after say going on two weeks, I'm back to the "On" and "Off" Restricted Performance. It will occassionally, say after an hour of driving, flash on for a few minutes then disappear. The CEL is back, and is staying however.

I know the best thing to do is get a diagnosic on it--which I hope to do sooner than later--but does anyone have even a "Sneaking Suspicion" of what this may be caused by? And/or what I may be able to do on my own..or my Local Mechanic...like cleaning a certain part etc etc?

Thanks in advance for help that is given!

 

cud be a knock sensor just going open circuit intermittently.. had that recently.. after an hour of driving.. its easier to scan it while its saying RP ..

 

Ah..Okay, well let's just say (Until I get that diagnostic accomplished) hypothetically it was or will be that Knock Sensor after all, would I just replace it...or can I simply clean it? Not very familiar with them or where I would fine them in the engine. Pic would be great.

 

Look under intake will see little wire bolted to the block
Replacement needed

 

It looks like I may need to purchase a unit, as no mechanics around here seem to have the chip or tech for their "General OBD II's" to read my unit. I went to one European Mechanic around here that mostly works on Volvo's and he was nice and tried hooking up his diagnostic tool, but it didn't work. Nada. He said it was because he didn't have the data to read a Jaguar, and thus didn't upload that into his system. What brand and or tool does everyone here recommend and of course, that will work on My 1999 Jaguar XJ8.

Thanks Much.

 

It seems odd you can't get anyone to read the code, I bought one of these in-expensive Code Scout readers a year ago and it's worked on everything except a newer nissan, even then although it couldn't tell me what the problem was, it gave me the code and I looked it up on line.

http://www.amazon.com/AutoXray-1500-.../dp/B0009XQUHK

I think auto parts stores like auto zone will rent code readers, no need to even buy one. If you want the full diagnostic capability the units can get quite expensive.