I purchased a used 2006 gmc sierra truck with the vortec 8100 8.1L/496 engine, 74000 files. Engine has always ran fine for me, never stumbled although my wife said it did the one time she drove it coasting down an exit ramp and it tripped P0101 and P0171 and P0174 all at same time.
On my way home with the truck when i got it, it threw P0101. Engine was under light load at the time, possibly coasting or just having let off the gas.
P0101 came back each time the truck was run for next few days.
I also received P0101 with either P0171 or P0174, but not both P0171 and P0174, sorry can't remember.
I have pulled apart the K&N cold air kit all the way to throttle body, cleaned and re-oiled filter and there is no excess oil. I reattached all the duct work, it goes filter - coupling - MAF - coupling - plastic duct 2 feet long from airbox location in corner to throttle body - coupling - throttle body. I have purchased the stock air box, but still need to get the stock duct, so i am still using the K&N setup.
I noticed some dirty water stains inside the coupler and MAF sensor. previous owner had put the cold air kit in and filter was somewhat exposed to road elements. I have corrected that so there should be no contamination.
I have cleaned the MAF twice with CRC MAF cleaner.
Also tried cleaning throttle body blade a little with MAF cleaner and rag, there was a little black on the outside edges of it. After this work P0101 became less frequent it seemed, I could drive the truck about 30 miles over a day and not have a CEL whereas before anytime i drove the truck more than 30 minutes or to/from work I would get the CEL.
I have an exhaust leak, the rear most exhaust manifold stud on passenger side is snapped and there's an audible tick when starting the truck and it's cold. After idling 2+ minutes it goes away, and once the truck is hot I can not hear anything.
most times it seemed P0101 would happen when under very light load constant speed or when letting off gas.
today getting on highway on stepped on it and accelerated pretty good from 30 to 60 mph, getting up around 3500 rpm. Once reaching 60mph maybe just before letting off gas engine light came on. this is the first time i've gotten P0137. I cannot tell if P0101 happened also, I have not cleared codes so it was still there on scan tool.
P0101- MAF signal not in predetermined range for more than 4 seconds
P0171 - O2 #1 bank 1 detected lean condition
P0174 - O2 #1 bank 2 detected lean condition
P0137 - O2 sensor #2 bank 1 low voltage for longer than 2 minutes
low voltage on O2 sensor = lean, correct?
I realize I cannot have an exhaust leak, or have a leak and not expect some codes to happen. I plan on pulling both heads and replacing all exhaust manifold studs when i can.
Do the codes I've seen so far jive or do I have other problems?
My plan is to pull both heads and replace all exhaust manifold fasteners and use new gaskets so there will be no chance of exhaust leaks there or at the collector between manifold and catalytic converter. I will also just put in two new front O2 sensors. Do you think i should do rear O2's as well?
On my way home with the truck when i got it, it threw P0101. Engine was under light load at the time, possibly coasting or just having let off the gas.
P0101 came back each time the truck was run for next few days.
I also received P0101 with either P0171 or P0174, but not both P0171 and P0174, sorry can't remember.
I have pulled apart the K&N cold air kit all the way to throttle body, cleaned and re-oiled filter and there is no excess oil. I reattached all the duct work, it goes filter - coupling - MAF - coupling - plastic duct 2 feet long from airbox location in corner to throttle body - coupling - throttle body. I have purchased the stock air box, but still need to get the stock duct, so i am still using the K&N setup.
I noticed some dirty water stains inside the coupler and MAF sensor. previous owner had put the cold air kit in and filter was somewhat exposed to road elements. I have corrected that so there should be no contamination.
I have cleaned the MAF twice with CRC MAF cleaner.
Also tried cleaning throttle body blade a little with MAF cleaner and rag, there was a little black on the outside edges of it. After this work P0101 became less frequent it seemed, I could drive the truck about 30 miles over a day and not have a CEL whereas before anytime i drove the truck more than 30 minutes or to/from work I would get the CEL.
I have an exhaust leak, the rear most exhaust manifold stud on passenger side is snapped and there's an audible tick when starting the truck and it's cold. After idling 2+ minutes it goes away, and once the truck is hot I can not hear anything.
most times it seemed P0101 would happen when under very light load constant speed or when letting off gas.
today getting on highway on stepped on it and accelerated pretty good from 30 to 60 mph, getting up around 3500 rpm. Once reaching 60mph maybe just before letting off gas engine light came on. this is the first time i've gotten P0137. I cannot tell if P0101 happened also, I have not cleared codes so it was still there on scan tool.
P0101- MAF signal not in predetermined range for more than 4 seconds
P0171 - O2 #1 bank 1 detected lean condition
P0174 - O2 #1 bank 2 detected lean condition
P0137 - O2 sensor #2 bank 1 low voltage for longer than 2 minutes
low voltage on O2 sensor = lean, correct?
I realize I cannot have an exhaust leak, or have a leak and not expect some codes to happen. I plan on pulling both heads and replacing all exhaust manifold studs when i can.
Do the codes I've seen so far jive or do I have other problems?
My plan is to pull both heads and replace all exhaust manifold fasteners and use new gaskets so there will be no chance of exhaust leaks there or at the collector between manifold and catalytic converter. I will also just put in two new front O2 sensors. Do you think i should do rear O2's as well?
