Gents;

At my wits end over here wresting lean codes on my 2006 LR3 with 232k on the clock. CEL has been on for almost a year, inspection is past due, and the part that sucks the most is that the car seemingly runs just fine. I’m lean on both banks with 171 and 174 codes - consistently.

Original mechanic claimed the MAF was the issue and replaced with a oem version. CEL was back within a week.

In the last three months I’ve done plugs, coils, a new battery, I’ve smoke tested and found the EGR valve and resonator both showing signs of a leak. I’ve replaced the EGR valve with an OEM valve, and gaskets. For good measure I’ve replaced the throttle body gasket. I’m confident I torqued those bolts to spec. I’ve smoke tested multiple times and I just don’t see a vacuum leak. * I am attaching the smoke machine to the air intake tube. (I mention this because could there be another place to smoke test that would show leaks elsewhere ? ). So- I’ve see Remedied issues (leaks) that shouldn’t have been there, but they don’t seem to have fixed my lean codes.

I’ve posted freeze frame data before - but haven’t really gotten a lot of useful feedback from it. It’s gibberish to me too.

What’s my next move ? When do I start turning fuel ? (And while we are at it - may as well mention I’ve already bought a fuel injector canister and run two cans through it. It seemed to have no impact).

 

I have the same issue and get a incorrect gear ratio code as well, here is what I have done so far

1. Replaced MAF
2. Checked for leak from air cleaner box to throttle body
3. Validated throttle cable tensioner was at .2
4. Replaced clamps on IAC
5. Cleaned IAC
6. Adaptive resets

To date - These have helped, however, at almost 44 miles driven, I get the check engine light for the lean codes. The gear ratio will be pending ever so often. My guess at this point and time is something is happening after the engine is at temp and something has expanded or contracted. Zero performance issues but, I am in the same boat as you.

 

There is a long thread about lean codes HERE after all of the things you have mentioned and a few dozen more were tried, in the end, an adaptive reset cleared the code. Not saying that was the main problem, but if the obvious things are fixed, it may be necessary to rest it to prevent the codes from coming back soon.

Long read but may help some.

Jeff

 

Assuming a V8, cause why would people actually say what they have, check the EGR tube near the back of the engine. Two bolts can loosen up causing a leak. Check over, very very carefully, all the intake tube plastics. They tend to crack near the metal ring support on the inside. Use a light. A tiny crack can cause a big issue. Check the PCV hose for cracks, damage or faulty o-rings.

 

Assuming you have no leaks, I would find a shop that can do a BG induction service and reset adaptions.

 

I read somewhere about a crack in the air tube near the MAF sensor