so I searched on all kinds of terms I could think of for this, didn't find much. '01 4.3, keep getting intermittant lean codes. replaced O2 sensor, no help. has clean filter. this started after a guy at an oil change place replaced the air filter and didn't get the elbow hooked right on the front of the TB, I fixed that no problem but now have a ongoing issue with the lean code.

I notice the air inlet elbow is loose on the TB, is there supposed to be a gasket under it? there's not. I tries to buy one but the chain store said there was no listing for any such gasket. I see there's like some kind of o-ring built into the elbow, nut it's not tight against the flange or the rim that sticks from the TB. Shouldn't it be tight one place or the other? BTW, it still has the tall plastic nut to on the elbow.

 

must be this thing:
ADAPTER. Air Cleaner Intake
ADAPTER,RR INT AIR DUCT(INCLS RETAINER,SEAL,RIVET). Required: 01For: ST1 4.3-X(LF6),4.3W(L35) (1996-1999) (1996 - 1999). For: ST1 4.3W(L35) (2000-2001... Show More

 

i just got rid of my lean code problem. i dont know what i did to fix it but i cleaned the maf it was dirty, also found 3 vacuum lines that were degraded and also put on a new pcv valve. remember when you clean the maf sensor use maf sensor cleaner or at least eletrical cleaner, DO NOT use carb cleaner. wait for the maf to dry then throw it back in and test it with new vac lines if there bad and also check the pcv valve to make sure its not full of gunk and oil.