I have a 2000 Disco 2 with 109,000 miles. I've been fighting a check engine light. I've searched and done the followed.
1-error code was p0174 for bank 2 lean condition (started to idle rough when in gear)
2-I removed my K&N filter and put in a paper filter and check for vacuum leaks (did this with visual inspection and spraying carb cleaner to see if idle increases). Found nothing.
3-cleaned my maf (which in turn made it idle even rougher)
4-replaced the maf with a used item off ebay (made the idle better)
5-replaced my front o2 sensors (with the miles, figured I needed this with the miles on it. It now runs better then I can remember.
6-cleared the code
7-light came back on and checked it, it's now po171 for bank 1 lean condition
8-decided I should have done all 4 02's at the same time, so I got the downstream o2's and replaced them.
9-cleared the code
10-po0171 is now back.

I hate dealers so anything that can keep me from going to them would be greatly appreciated!

 

I'm doing the exact same thing. Check for vacuum leaks as that seems to be the issue with mine. Look at the cigar test.

Mike

 

thanks, i'll do that!

 

I did the cigar test and didn't find any leaks. ANy other input would be greatly appreciated .

Thanks!

 

Update, I went through and re-checked/tightened all clamps for my vaccum lines and made sure they are on tight. Went and check my codes and it's p0174 for bank 2 now. I really don't know what else to look at. It's running great. I really need some help.

Thanks!

 

Still sounds like a vacuum leak somewhere IMO. Also check for any exhaust leaks pre sensors.

 

Leaks in the exhuast? Maybe a cracked or leaking manifold or maybe leaks where the manifold attaches to exhaust?

 

I'll check out the manifolds. I looked at my cats and they look great still.

Thanks guys!

 

Update folks. I had a broken exhaust stud on the left manifold. I pulled the manifold, checked for cracks, no cracks on it. Replaced the gaskets, re-installed and tightened it. Cleared the p0171 code and drove 30 miles and it's back. Anything else people?

 

Side note, my valve covers are leaking, so i'll tighten them this weekend, but I wouldn't think that would cause a leak to cause the p0171/p0174