!!!!!!!!!!!!!!!!!IT'S ALL FIXED!!!!!!!!!!!!!!




Alright I have read a lot of forums have taken it to two shops and have fixed quite a bit of things still cant get codes to go away. I have been dealing with this for a few months now and can't figure it out. I have a brand New MAF according to shop the shop it was last at it is getting normal signal from the O2 sensors so those don't seem to be bad have had two smoke test done and have had all leaks eradicated and still have codes. Last shop has ran two full tanks of as with a fuel injector cleaner in it to try to see if that helped and they keep coming back. I can get about 100 miles before the code comes back. I need some help to point me in the right direction to where or what i should be looking for.

It is a 2003 Disco 2
125,000 Miles roughly
Head gaskets spark plugs/wires done @100,000mi
New O2 sensors around 90,000mi

Let me know what other info would be helpful


Thank you in advance for the help.

 

Report back after the MAF replacement.

I had both codes. Cleaned my MAF and they havent been back since.

 

I have a new MAF on it and all new vacuum lines

 

What are your long & short term fuel trim measurements for each bank? I know you replaced the MAF sensor, but was brand/part number was it?

Have you examined the tube between the MAF and throttle body? Smoke tests usually don't evaluate this section, and I have seen cracks here in the past.

 

I will have to get back to you on the fuel trim measurements for each bank but the MAF was replaced by a independant Land Rover Shop. It wasn't a knock off or the one for the 4.0, so I am assuming they put the right one in. I will check that section of the intake later today.

 

Was the smoke test done with a "professional" machine or with a cigar and your lungs? A friend of mine had the same problem and although we did our best with a cigar one Sunday afternoon we never did locate the leaks. A couple years have now passed and he long since sold the truck without solving the problem, but based on continued reading on this forum I am now convinced that his problem was the fuel injector O-rings. For one thing they are more difficult to detect with a cigar smoke test, and, like you we had eliminated everything else.

 

it was done at a shop I wasn't there to say for sure but I was told there were no leaks and I am assuming it was done the right way

 

alright so I drove around with my ultra gauge watching the fuel trim I have a few videos of the readings but I'm not sure what they mean. If anyone can help I can email or text it to them

 

You have short term and long term numbers? Post it on youtube.

In general, your long term numbers shouldn't be much outside the range of -3% to +3%. Any greater discrepancy and your ECU is likely compensating for an issue(other than it being an old truck). Short term can vary much more, but dead spots or big variances from cylinder to cylinder can indicate a bad sensor. The best way to look at short term is to graph the values, using Torque app or something similar.

 

Just incase anyone else is having this issue it has been fixed. Brake booster was bad and was leaking so as I pressed on the brakes it was sucking in air causing lean fuel codes. So New Brake Booster is on and codes are gone.