Persistent restricted performance... Charged air filter and cleaned maf, solved it for 4 days and now it's back with a vengeance...

 

What codes are you getting ?

 

Have a look at the video.
https://www.jaguarforums.com/forum/x...ir-leak-87618/
You can get STFTs and LTFTs using an app called 'Torque' on an Android phone and a very cheap Bluetooth OBD adaptor.

 

p1174

 

Okay, I'll spill the beans, but nobody laugh please. I found a utube on making your own smoke leak detector and it worked for me. I took the part load breather hose off at the valve/cam cover in front. Put a short length of rubber hose on it - just to keep it clean. Took the intake tube off right where it joins the air box and put a rubber glove tightly over the intake tube. Cover or tightly plug the hole where the part load breather went. Then take a cigar, and start blowing smoke into the rubber hose on the part load breather hose. Everything needs to be sealed. You will see the rubber glove inflate on the intake tube. Then hold your finger over the end of the rubber hose and as the rubber glove deflates, you should be able to see a wisp of smoke somewhere, or hear a hiss. I got my son to help since he has sharp eyes. Once spotted, it's easy to verify the leak. It may take a few puffs on the cigar. Mine was the intake manifold, unfortunately. But with a used IM off fleabay, some new seals and my own diagnostic work, I'm sure I saved myself a bundle. Bubba might've replaced every vacuum-related item on the car as well as MAF, injectors and who knows what else. I had tried carb cleaner and propane along with my OBD reader and fuel trims with no joy. Leak was underneath the IM.

 

No laughs here. Cigar test works, it's simple, cheap, and I smoke them anyway. Without this, one might hunt for the leak for days. Latex glove is a good idea, I had a hard time convincing my wife that the condom in the tool kit is there for a car diagnostic. She let it go after a fit, but I don't think she believes me to this day.