Hello all, I've searched the forums. I understand p1171 usually comes with p1174. Any recommendations on how to mend it? Trucks having no performance issues. My mechanic says it's an O2 sensor, is this correct?

Thanks

03 128k

 

P1171 is lean both banks, if I'm not mistaken.

1 O2 sensor wont cause a lean condition on both banks. You either have a MAF issue, a vacuum, intake or exhaust leak, or a fueling problem.

If you have no other codes, eliminate fueling. leaving MAF or leaks.
I cleaned my MAF and left it out of the truck for a day to dry. Hasn't returned.

I also bought a a paint can smoke machine in anticipation that it may have been a leak somewhere in the intake or exhaust, but it never returned (And now i have no reason to use my new toy/tool)

Results may vary.

 

^^ Sound advice. ^^ Check your intake plenum for leaks at every point where there is a hose connection. Sometimes removing the plenum for an off-vehicle inspection turns up cracks or bad joints; take a careful look.

 

Any recent mx such as air filter change? As previous reply suggested check for leaks. Found mine at SAI elbows.
......

 

Thanks, I'll start with the MAF too

 

You are mistaken.

From the RAVE - "P1171 System too lean (bank 1) Additive injector adaptive fueling - lean limit exceeded LH bank"

 

Before changing any parts, check out the fuel trims to make sure it's only lean on one bank. I just got a P0174 code, or lean code for bank two, but bank one is not far behind. The fuel trims were 23% on bank one and over 25% on bank two.

 

I stand corrected.

Air leak or O2 sensor.

 

Please help me find this in RAVE. Where is the list of DTCs?

 

Trouble code tables appear in several places in the RAVE depending on the system in question (e.g. brakes, transmission, restraints, etc.)

The P1171 and related codes are in the Engine Management System section, Description (page 334 of my RAVE PDF).

I always just use the search function to find whatever code I'm looking for.