don't know where to start..

[white 98 gt]

so i got a cel code of 1151. says it's the o2 sensor bank 2 sensor 1. lean. probable causes are supposed to be: leaking injector, dirty maf, vacuum leak. cleaned maf a few months ago, can't find any vacuum leaks. mechanic at work says could be an injector, that it's dripping instead of a spray pattern. called a shop today that's familiar with ford 4.6's & he said it could be a dirty egr, even if it's not throwing a code for the egr. when i take off it's fine, but at highway speed it'll buck sometimes then i get the cel on. getting frustrated with this. i can fix it if i know what to fix. anybody have an idea of what i should lean more towards? thanks for any help. oh, mechanic also said could possibly be 1 of the coil packs also... :BangHead:

 

[96gtchinook]

most likely a vacuum leak check around throttle body and if you want to check EGR/IAC but i bet you have a brittle line there with a small crack. Just fixed an oldsmobile this weekend with a similar code and it was sucking in air big time.

 

[white 98 gt]

ok man, i'll give that a try...

 

[Pennywise2]

Sounds like a vacuum leak around the intake plenum area.
I bet you have a cracked hose somewhere.

 

[gearhead]

Can you see if the O2 is switching like it should be?

 

[white 98 gt]

Can you see if the O2 is switching like it should be?

i don't know how to check that. something i forgot to mention before: it seems to do it worse when it rains or when alot of humidity is out. i'm leaning towards the coil pack(s) or sparkplug wires...what ya think?

 

[gearhead]

If humidity or rain is a factor than look close at your plug wires for sure. I'd say that's the most likely culprit if it does it more when it's wet.

 

[AaRoN]

Start your car, open the hood and, with a spray bottle, mist over the plug wires. If one of them is cracked or broken, they'll arc and you will see it.

 

[vermilion]

egr issues would throw a p0174 code on lean conditions on both banks. along with associated egr valve code and insufficient airflow. also, a leaking throttle body and elbow would also trip a p0174 without egr codes. vacuum lines or weaker injectors will throw a lean code among other miscellaneous codes. you can use carb and choke cleaner for any vacuum issues. i ggogled this p1151 code to come to:

Short to VPWR in the harness or HO2S
Water in the harness connector
Open/shorted HO2S circuit
Corrosion or poor mating terminals and wiring
Damaged HO2S
Damaged PCM
Fuel System:
Excessive fuel pressure
Leaking/contaminated fuel injectors
Leaking fuel pressure regulator
Low fuel pressure or running out of fuel
Vapor recovery system
Induction System:
Air leaks after the MAF
Vacuum Leaks
PCV system:
Improperly seated engine oil dipstick
EGR System:
Leaking gasket
Stuck EGR valve
Leaking diaphragm or EVR
Base Engine:
Oil overfill
Cam Timing
Cylinder compression
Exhaust leaks before or near the HO2S(s)

 

[white 98 gt]

i'm gonna clean my egr valve. can i use carb cleaner? one guy at a parts store said not to use that, but manifold cleaner(?)..

 

[white 98 gt]

btw, thanks to all who responded. i'll eventually get it figured out & when i do i'll post what fixed it for future reference for someone else..