Discovery II, codes PO171 & PO174
 

2000 Discovery II with 82,000 miles
I have two codes PO 171 and PO174. where do i look, MAF or plugs and wires??

RE: Discovery II, codes PO171 & PO174
 

P0171 - Oxygen Sensor System Too Lean Fault Bank A
P0174 - Oxygen Sensor System Too Lean Fault Bank B

Not really sure where to tell you to start to look to troubleshoot the problems. Thought I would post what those codes mean so someone else can chime in with ideas to fix the problem.

RE: Discovery II, codes PO171 & PO174
 

Seafoam It

RE: Discovery II, codes PO171 & PO174
 

Probably the MAF sensor, make sure you get a Bosch one, not aftermarket. How often does it come back after you erase it? If not too often, I would hold off until I got a 3rd or 4th gear ratio code too. Also look for vacuum leaks after the MAF sensor.

RE: Discovery II, codes PO171 & PO174
 

Thank you

RE: Discovery II, codes PO171 & PO174
 

Seafoam, is this gas treatment & who carrry this product?

RE: Discovery II, codes PO171 & PO174
 

Search for seafoam on this forum, there are several pages worth of how-to's and general information on it.

The MAF is the most likely culprit. www.roverlandparts.com sells used ones.

Cheers,

Pete

RE: Discovery II, codes PO171 & PO174
 

PM me with your tele number and we can talk more about how to check and what to replace.

RE: Discovery II, codes PO171 & PO174
 

And for the rest of us who want to know what to do next?

RE: Discovery II, codes PO171 & PO174
 

When both codes show up together, if the MAF hasn't failed, then I would look for air leaks from the filter box to the t/body.