97 - Check Engine Light! Lean on Bank 2, O2 Sensor?

[dash14251]

ok, i got a check engine light and got the free diagnostic done at advance. it said Lean Bank 2 or something to that effect. the guy said maybe a leak in the exhaust somewhere or an O2 sensor or whatever, he didnt seem that helpful. there are 4 o2 sensors (2 before cat and 2 after). i dont want to buy all 4, so does Bank 2 mean something as far as which sensor or which side of the engine it is talking about?
thanks

[rodeo02]

You need to have the actual code to know what oxygen sensor the code is coming from. Autozone will give you the code. Typically a vacuum leak will give you a lean code, but it could also be a fuel delivery concern. Gotta start with the code.
G/luck
Joel

[dash14251]

i found the thing they print out and give you, heres what it says:
----------------------------------------------
DTC (Codes)

P0174
System Too Lean
(Bank 2)


DTC Pending (Codes)

P0174
System Too Lean
(Bank 2)
----------------------------------------------

i guess thats the code P0174. does that mean anything to you? thanks for your help!

[travelman]

Bank 2 is on the driver's side. Like already noted, check for a vacuum leak. On the 3.5 a likely cause is a bad intake manifold gasket. I don't think this is a known problem in the 3.2 though.

[rodeo02]

Originally Posted by travelman

Bank 2 is on the driver's side. Like already noted, check for a vacuum leak. On the 3.5 a likely cause is a bad intake manifold gasket. I don't think this is a known problem in the 3.2 though.

Check around the upper intake/common chamber on the driver's side for vac leaks around any tubing and/or fittings on the 3 runners for that side. IIRC- this might be a PITA because the throttle body sticks out that side. Only other things I could think of is maybe a weak or clogged fuel injector on that side, or as a last resort, a bad O2 sensor?? *usually* you'll get a "no activity" code from a bad O2 sensor though .

G/luck
Joel

[jamfu]

I am having the same trouble with my f150. And it is fairly easy to rule out a few things if you get a vaccum gauge and a dmm. The vacuum should stay at about 20in hg at idle. Note: A slight increase and decrease of a couple in signals a leak. You will want someone to rev the engine up to about 2500rpm quickly. the gauge should go to close to nothing, go beyond the 20in hg then return to 20. Also, pull the pcv valve off while the engine is running to make sure it is sucking. If not, replace it. Next, with your dmm check voltages and resitences to the tps, iac.