Lean codes. What procedure in finding cause? Thanks. I have searched and found tons of things but where to start first?

 

Any other codes along with those? Start with a vacuum leak check and see if any other codes show up, if they do get back to us with any new numbers.

 

No other codes just those 2 and sometimes only 1171

 

I'll check for vacuum leaks in the morning

 

I had the same codes and after a smoke test with a cigar I found I had a small vacuum leak where the air intake tube connects to the throttle body.

Check out this thread I made awhile back to help you out.
https://landroverforums.com/forum/di...s-cigar-54235/

 

I had the same codes also. Usually 1171 and sometimes 1174. Mine ended up being the intake tube also.

 

Nice tightened up all intake hoses no more codes yet after 3 days of driving. Thanks y'all

 

Back now getting 1171 1174 1412 and 1415

 

OK this issue is caused by three major possibilities
1. Bad fuel pressure. ...
major cause would be a bad fuel pump and/ or filter.

2. unmeasured air going in the the cylinders,
major cause a vacuum leak

3. the meter that measures air not working
major cause MAF or MAF plug


First thing to do is to get a good code read, a code could help you pin point the issue, an example is a scanner can tell you is the signal from the MAf is is present. bad or intermintant.

Next smoke test your air intake. this is a good video that explains vacuum leak possibilities



finally have some ine pressure test your fuel.

 

Finally this video explains the lean on both banks issue,

the p0174 and p0171 are the same as the two you have