1. Got the new MAF and installed it.
2. Cleared faults with IID tool while engine was off.
3. Reset adaptive values.
4. Turned the truck on and went for a drive.

Engine light is back on with the same codes. Took about 20 min and 10 miles to trigger it.

Revisited my service records and confirmed all new hoses, 8 new plugs and coils which was all done in 2019 or more recently and for sure it's been way under 100,000 miles since they were done. I replaced the air filter last summer prior to a 2,000 mile trip in 5 days. Do I need a new one (it looks clean).

Now what?

 

Air filter would cause rich issue if congested because of lack of air, not a lean code which is too much air. At this point, you just must have an air leak. Did you replace the PCV as mentioned? Other things to check, oil filter cap on right and good. Oil dip stick o-ring good. Remove the air intake ductwork after the air box and inspect every inch carefully for cracks, mainly under the metal clamps. There is a metal ring on the inside under the clamps. Issue is the plastic shrinks a little, ring does not and you get cracks. Or people over-tighten the worm ring. Also inspect the rubber gasket at the intake tube to filter box. On the back of the engine on teh driver side is the other end of the EGR tube, make sure both bolts are tight. 10mm maybe... You may even wan to consider the EGR valve itself being defective, but that usually throws out a code.

 

Thanks Dakota, I appreciate it.

I'll go searching again tomorrow and take everything off from air box to throttle body and post back.

The filler cap was on and the o-ring on that and the dip looked ok without an obvious tear but I'll look more closely.

The PCV was also done at the same time as the plugs, coils, hoses and all the rest so I did not replace that.

Good thing I've always wanted a car I could work on. 😜

 

Oops, forgot to ask.

Is there a live value I should watch on the IID Tool to verify it's within or out of range?

 

Oops, read over that about the PCV. These trucks are stupid sensitive to vacuum leaks. Mine wont even run with the oil filler cap off. And the PCV is so dang noisy, you can not hear over it for a vacuum leak.

 

Good question, it would maybe be for the MAP sensor? I think that reads vacuum, first vehicle with one so I forget its there. But I never read it, so not really sure. You may have to do some digging on that unless someone else can give some details.

 

Ok - I'll do some searching on the vacuum values.

Confused about your PCV post. Should I grab a new one?

 

Well I couldn't wait so I took it apart. Nothing looks cracked with maybe the exception of the inside of the boot that compresses onto the throttle body. There's a close up of the weirdness below.

I removed everything then cleaned it up for a better view. All the rubber gaskets look good and do not have cracking at all. The hose from the boot by the TB that goes to the back of the engine looks ok too. It's got some scratches on its top but nothing deep, it all looks superficial.

I also checked the o-rings for the oil filler cap and dip stick. Both looked brand new. I did find some small amount of crusty crud on the top of the ring of the filler cap. Cleaned the o-rings on both as well as the outside and insides of each hole. I was very carful not to let anything get inside and nothing did.

I'll go hunt down a smoke machine now to rule that out I guess.



Air Box connection

Air box side of resonator.

Boot from resonator to throttle body.

Inside of boot where it connects to throttle body.

Inside of boot to throttle body where the hose to the back of the engine goes.

 

The most common place for cracks is on the middle plenum, they often crack at either end. The smallest crack can be a big issue, think hole in straw when drinking. So if you did not notice any, then you are probably okay there.

https://landroverforums.com/forum/lr...sonator-91604/

 

Didn't see any there, especially as what was shown in the link you posted.

I'll look again tomorrow with fresh eyes and smoke.