I feel like this was brought up before but its not in this specific post. Have you inspected the intake plastics? They can crack and like a straw with a tiny hole it can have a massive impact. They seem to crack around the ens where there is an internal metal support ring. Like the plastic shrink and the metal ring prevents contraction resulting in cracks. Also the rubber pipe gaskets are not the best.

Also check the far end of the EGR pipe behind the engine, the two bolts can come loose.

Have you replaced or verified MAP sensor function? I would expect a MAP code but if its being lazy and won't throw a code it could certainly adversely affect things, but then I would also expect rich codes. Its hell to get to, I have a thread on it with some pics. Given that you only have lean codes, I would not necessarily put this high on the list.

Overall with lean codes though its almost always unmetered air entering the system. If you can drop the hammer and she moves good at WOT, I doubt fuel issues since WOT should cause starvation.

 

I can not say with confidence that the tool WILL solve this specific issue.

But

I CAN say with confidence that this tool is an indispensable and essential item in your toolkit - it can perform a multitude of functions that cost $$$ at dealers or Indys.
It's a case of spending $500 up front to save you potential $1000s in the long run - without ever leaving your garage.

 

Oh, forgot to add to my list to check the oil dip stick and oil filler neck and cap. Both of those can cause a vacuum leak.

 

I have the same recurring issue with my '05 SE 4.4 and have replaced the MAF sensor with a Denso unit, the upstream 02 sensors with Denso units, Throttle body metal gasket, re-fitted all air intake plastic tubes, fixed the screw hole holding MAF in place since it was not tightening the sensor so causing air leak when the airbox vibrates or moves around when I hit a bump. Engine runs smooth and gas mileage is normal but CEL keeps coming back after about 10 to 15 miles of driving so I will be performing the adaptations reset. I do not have the $500 tool but you can get the lesser expensive one from Atlantic British for $399.95. I know I will probably get flak for this but I opted for a Chinese version that has a downloadable software which does everything that the more expensive ones do so I will see if it does the trick. On a side note, has anyone ever adjusted their headlights on rigs with 2.5 inch lift? I have not seen any post regarding this matter.

 

Well... my saga continues as well. Dropped the kids off this morning and noticed I had the little info icon in my dash cluster. Scrolled through the screens and lo and behold "Fuel cap loose or missing" warning pops up! At least I have two years to fix before the next emissions inspection is due.

 

Lean Codes SOLVED.

Vacuum Leak. I know that sounds silly, cause I did EVERYTHING to find said-leak with the smoke testers that I know own, but here is where I went wrong.

The obvious place to connect the smoke machine is the Air Intake Hose, which is after the Air Resonator (Believe it's called). Short of the long is - I believe there was a crack at the end of the hose.

Last installment - and before you watch - a few things....

This was intended to be a temporary fix just to get my CEL off and for me to get inspected. I intend to order a new Air Intake Hose this week. I am 150 miles with the CEL off - with my fuel trims looking dramatically better than they previously were.

 

Great news! Looks like DakotaTravlr was right. Intake plastics for the win.

 

I wish someone would have mentioned the intake plastics earlier...

https://landroverforums.com/forum/lr...51/#post717941

Or even back then...

https://landroverforums.com/forum/lr...09/#post701015

 

Funny guy...@ Dakotravler

Like I said - inspected a million times.

The critical piece of information here is that inspecting your plastics may not yield an obvious fracture and replacing the pieces, almost as preventative is not a bad idea.

looking back at your comment - well done. That was exactly where the issue is. Wish I was wise enough to know what the hell it meant.