Suddenly started experiencing rough idle so began research. Cleaned TB and MAF with no change (although both needed it). Thought dirty injectors so ran a can of BG44K through it also no change. Pulled codes and get:
P0305 Cylinder 5 Misfire Detected
P0316 Misfire Detected On Startup
P0174 System Too Lean (Bank 2)
P0171 SyStem Too Lean (Bank 1)

Removed #5 coil and spark plug. Per Atlantic British coil test I plugged in spark plug to coil (pulled fuel pump cross-over) then cranked while grounded and it sparks so thinking coil is good. Just to be sure I swapped it with #3 and put it all back together and no change. I drove it a while then pulled codes. This time I get:
P0307 Cylinder 7 Misfire
P0303 Cylinder 3 Misfire
P0300 Random Misfire Detected
P0316 Misfire Detected on Startup
P0174 System Too Lean (Bank 2)
P0171 System Too Lean (Bank 1)

So now I'm stumped and not sure what to do next. The misfire did follow the coil from 5 to 3 but it functioned properly when tested with spark plug so wasn't expecting that? Now misfire on 7 and the P0300 is new. I've found a few posts mentioning EGR valve? Also not sure it means anything here but did have P0441 Evaporative Emission System Incorrect Purge Flow code the first time but didn't return on second read. Really appreciate any thoughts on what next?

 

I have had the same misfortune as you. All those added up to a stuck open EGR valve for me causing a lean condition and a misfire. I finally bit the bullet and bought a new EGR valve and PCV from RockAuto after removing the EGR and cleaning it with no change. Brought it back to my local LR shop, cleared the codes and all that is left is no.8 misfire and I can't get the coil bolt out to change it..

 

I did a search on these forums for egr replacement and found nothing... could anyone provide a description of the location of the egr and/or pcv and possibly part numbers?
Thanx...

 

Don't have part numbers but RockAuto has both and reasonable price.

Think I've narrowed it down to a vacuum leak. Used advice from other members for cheap test (plug intake with an old oil filter or can...wrap in duct tape to make snug fit if needed), start and listen for squeal indicating air being sucked in from the leak. Noticeable squeal just doesn't run long enough to pinpoint exact location. Think it's PCV so starting with replacing that this weekend. Also going to change spark plugs since they are overdue. From what I can tell since buying few months ago they haven't been changed in a while or perhaps original.

 

For anyone that was following wanted to close part of the loop. Over the weekend I replaced spark plugs, PCV, and no. 3 ignition coil. Believe my misfire codes was the coil. Cleared up the rough idle and no codes. However, CEL did come back on after driving about 20 mins with P0171/P0174 so still troubleshooting. Had recently cleaned MAF, TB, and looked for vacuum leaks. Thinking I still have a leak not found yet, perhaps MAF needs replacing, or have read some threads that fuel adaptations need to be cleared to be certain there is still a problem.

 

The spark plug test only works if your coil is completely dead. It doesn't work with intermittent misfires, which is why moving it to another cylinder is key. If the misfire follows the movement, then the coil is bad, as you found out.

As for the lean codes, I rarely find that "cleaning" the MAF does any good. If the MAF is skewed, it usually ends up getting replaced.
Resetting the adaptations after each component substitution/replacement is important. Even if you replace the offending part, learned fuel trims will cause the faults to reset until the car has been driven long enough for the fuel trims to learn and adapt to the new part.
If you have no way to reset the fuel trims yourself, I'd keep clearing codes 2-3 times before I assume the part did or did not fix the issues. If you have some sort of diagnostic tool, you can get a good idea of the changes by watching the fuel trims.

 

Thank you for confirming what I suspected. Should have just followed what I learned from folks like yourself and trusted that. Threw me off a bit when the misfire did move with ignition but another appeared. Think the sudden appearance of no. 7 misfire was bad spark plug. It was in pretty bad shape when I changed them...more so than the rest which leaves me a bit concerned.


Have read your advice on the MAF and understand that cleaning rarely solves issues. I don't have a diagnostic tool yet so hard to get the information I really need and do the resets properly. I'll keep trying to clear the codes or thought about checking with the local indy shop with good LR reputation and asking if they would provide some diagnostic data and clear it all.

 

Just wondering if a hard reset will reset the fuel trims?

 

If you do it long enough, yes. I don't know what the threshold is for that to happen, though. On older Jags, a battery reset was the only way. I'd recommend at least 30 minutes?