Hi All. Great Forum here. This is my first post, Hope you can help.
I bought a 2001 Disco about a month ago. I love this thing but I’ve run into a dilemma.

Last week, the “Service Engine Soon” light came on. I did a lot of reading on this site (and others) and decided to buy a Code Reader. Upon hooking it up, I got these codes:
P0734 “Incorrect Gear 4 Ratio”
P0174 “System Too Lean (Bank 2)”
P0171 “System Too Lean (Bank 1)”
Reading from other posts, this is a classic MAF fault.

I went out and bought CRC Mass Air Flow Sensor Cleaner, removed the MAF and went to town on it. It didn’t appear too dirty before I cleaned it and to be honest, it didn’t look much different cleaned up. I then re-installed the MAF and reset the SES light.

Well the light came on again after a short 6 mile trip. Same 3 codes again.

So, should I get a new MAF ($125)? The Disco has 80k miles and the service records were last kept up to date at 37.5k miles. Think it’s possible I need O2 sensors as well? Should I just get the fronts or replace them all? Is there anything else besides these parts which will return these particular codes?

Oh yeah, when I put my reader in "Live" mode, I get a reading of my MAF as 0.000 lb/min.

I hate just throwing parts on and hoping to fix the problem.

Thanks
Jules