P0171 & P0174 Codes

[BradE.]

My CEL came on with a P0171 and P0174 codes, system lean bank 1 and 2. This is normally part of the lower intake manifold o-ring problem on the SOHC engines, but here's the catch, I have an OHV.

I checked my voltage at the MAF and it's within spec, the air flow rate at hot idle is within spec too. It's 17 degrees right now, so really can't get out and test too much stuff. The intake manifold bolts looked tight, will verify tomorrow. The only thing I can think of is air is getting sucked in somewhere and leaning it out.

Anybody else deal with this problem on a OHV?

 

[Jonny813]

I have the same problem, and pretty much the same vehicle. My fuel filter is the original one, never touched in 125K miles and I'm almost positive thats whats wrong with mine. I haven't got around to installing a new one yet, but you can give it a shot if you haven't replaced one yet... they are less than 7 bucks... And the tool, if you dont already have it is like 6 bucks... And if you don't have one, avoid the single metal tool that looks like a funnel... the metal one will not fit on the rear side of the filter.

 

[TPLYNCH]

Try tightening the intake manifold bolts, even if they look tight. Also, make sure there are no holes/cracks in the intake plenum after the MAF to the throttle body. You should also try testing to see if there is a leak at the intake manifold, spraying (? can't remember what has been suggested) around it while the engine runs, listening for change in the idle.

 

[BradE.]

I checked all the vac hoses, the PCV valve and others, no code yet. The hose from the air intake tube to the oil filler was a little loose, so I put that back tight. If it comes back I'm moving to the intake manifold bolts and will probably replace the IAC too.