P0171-P0174 Lean Condition I know there is tons o info on these but i'll add some findings and when it's fixed maybe it'll help someone else. Removed intake manifold today to inspect PCV and hoses.PCV systems= Good. O2 Sensors=Good. Maf sensor=Good.Vacuume hoses and connections=Good,Vacuum readings, low 50s and steady.Next will be fuel pressure checks and coolant temp sensor.Update tomorrow...James

 

I get those codes too and did the same thing, everything seemed to check out OK. One thing I did discover though is that the Cat. converters had been chopped out by a previous owner, I'm wondering if that would cause those readings?

 

I,m thinkin about a possible partial restriction in the cat and am going to look at that also,I've noticed a gradual loss of power in the last couple months.

 

A guy that helps me with my truck suggested that because my cats were cut out it just might be why I always get those codes, but I haven't had any real noticable horsepower problems, So I'm just guessing thats why mine throws up those codes.

 

I,m no expert but there seems to be alot of info about this topic in the search feature with some succes in PCV, Maf cleaning and a couple other fixes but alot of posts of people lookin for solutions. I,m thinkin i'll check fuel pressure,cts,cats next.

Keep you posted