Hi All

Well i have been working on fixing the original stuttering and misfire on my 2007 Jag X type.

so far what i have done is:

1. Replaced all Ignition Coils with brand new ones.
2. Replaced all Spark Plugs with Champion Iridium one ( found out that bank one (Cyl 1,3 & 5) was running lean upon removal of the plugs bank 2 (cyl 2,4 &6 fine).
3. Replaced both upper and lower inlet manifold gaskets with genuine Jaguar ones - saw an immediate improvement in performance the old ones were shot!
4. Replaced O rings in the top of the inlet manifold again with genuine Jaguar part after having a smoke test carried out.
5. Bank 1 O2 sensor replaced with new Jaguar one after getting a code P0037

The only readings i ma now getting off my OBD11 reader are

P3000 Random Misfire on cylinders
P0303 & P0305 Misfire Cylinder 3 & 5
P1313 - Jaguar - Misfire Catalyst Damage Bank No. 1
P0420 - Jaguar - Catalyst System efficiency below threshold Bank 1

I have read that a poor or stuffed Cat can cause a misfire - is this correct?

Some days she doesn't misfire at all other days she can be very awkward and splutter/stutter a bit - take throttle off and rive slow then she will be fine?

Phoned Brisbane City Jaguar this morning to ask how much a full diagnostic test would be with a printed report AU$232 - Just wondering if it is worth me spending the $232 to get a proper Jaguar report or weather I trust my own OBD11 device? or do I just replace the cat or take it out totally?

My wife also drives the car and doesn't get a misfire, but I do LOL, maybe cause i ask for more power than her at times, I have also noticed that if I do drive her then she does tent to play up more, if i just doordle around and drive it very sedately she doesn't misfire!

Could it be the PCV valve?

Any help would be greatly appreciated

 

My son has had a similar fault on his Ford "same engine" first time was leaking vac pipe which was almost impossible to get at!
Local ford main agent fixed it £600
Second time similar fault suspect same leaking pipe. Local Pakistani garage fixed it £48.