What do codes B2AAA and B2A00 mean?

SOURCE: 1996 GMC Sierra 1500 truck fuel problem

Have you check the injector relay or maybe a fuse for injectors.

SOURCE: Check engine light is on and high idle (1500rpm)

Some times the E.G.R. will stick half open. This will make the engine surge or have high idle. Try replaceing the E.G.R. located under the upper intake. Do not go with after market E.G.R. The spring in them are to powrefil and the E.G.R. wil not open. Also try replaceing the O2 sensors. This could give the engine more fuel thus a higher idle. Some vehicles the T.P.S. can be ajusted, do some checking to see if yours is adjustable.

Please contact me if your problem presists.
Thanks, Charlie

SOURCE: My gmc envoy idles rough and the ses light pop on with a p015

See or call your local auto parts store such as AutoZone or O'Reillys for the trouble code definition. Also, make sure your gas cap is really secure, and I mean tight.
Rick

SOURCE: Code P0121 on 2006 GMC

Classic signs of idle air control not able to cope with sudden engine loads. Cleaning should resolve this. Remove ducting from air cleaner to throttle entrance. Spray with carb. choke cleaner or WD40 spray and wipe back to the alloy finish. clean the the throttle plate and push the throttle open with your fingers and clean in behind as best you can. Clean the passageways to the idle air control valve. Remove the valve and give it a thorough clean up. Reassemble and it should all be good.

SOURCE: 2003 GMC Sierra Has recently developed

You never replace anything, on a Wishing,Hoping,Pushing,Poking,diagnostic approach

You learn the vehicles Systems,Test,then Replace,if you have a failed component.

Work on the Misfire Issues.
Then you lean O2 Codes will go away.

Not a the plugs.

Think lean---Vacuum leaks,EGR Valve leak,EVAP System leaks,anything with a hose that lets air into the intake system.
Exhaust System leaks,near sensors