Ron_Stoppable

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I have a 1998 sonoma with a 5.3 swap LS1 intake ect I bought a brand new dorman MAF for it off of rockauto. The truck keeps throwing P0101 and 2 codes that says both cylinder banks are running lean which are P0171 & P0174. I checked power and ground to the sensor and they both checked out good. Please dont bash me but... I did have to reuse 1 intake manifold gasket because I bought a set of the blue fel pro gaskets from oreillys and it only came with 7. I tried to take them back but they thought I was lying. Can that cause these codes im getting.

Ed Wright

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I have no experience with a Dorman MAF, but it could be all your problems. Home made air filter and intake ducting can also cause both. When people bring their late model trucks here for tuning with "cold air kits", I have to re-scale the MAF tables to correct that. Hard to tell them the factory air filter system is "cold air". LOL Some popular kits actually cause the codes you are seeing. I see the same issues with engine swaps and home ducting. People don't seem to get that how the air is aimed through the meter effects it's calibration. You may just need the tuning altered to get your trims back in line. Next time, just to be safe, buy a MAF from the GM dealer instead of the cheapest you can find.

Mike@Diablosport

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I think dorman is an OE replacement part?

Either way, Ed's right, it could be the MAF, but those codes would also come up from bunk intake gaskets as well, although it would likely just throw a lean code for the one bank.

Any high idle issues?
Check all the connections on the intake coupling as well.

Ron_Stoppable

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I tested all the wires and grounds and got the correct voltage on them all.... 5v on sensor signal wires and 12v on the pink. The ground wires also checked out good. Truck idles at about 800-900 rpm solid. When I unplugged the sensor I could definitely hear a difference in idle especially with light opening of the throttle... idk what to do!!! Is it the sensor? Its throwing P0101 and P0102 along with P0171 & P0174

Undertow74

iTrader: (45)

stupid question but what do your 02's look like? or you very well might have a vacuum leak. did you try feeling around the manifold or spraying some carb cleaner to see if the idle changes?

Ron_Stoppable

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I got the 02s from a silverado at the junkyard because I couldnt afford new ones at the time. If they were bad wouldnt it throw a code though?

Ed Wright

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It's not your O2s.

Engine swaps, due to home engineered or adapted inlet ducting, modified engines, and/or many aftermarket (crap) "cold air" kits (Ray Charles, in his present condition can tell the original system is "cold air") often cause P0101 to set. Either alter the test parameters or just shut the code off. Those crap "cold air" kits often cause lean codes & require re-scaling the lower end of the MAF table to correct the low indicated air flow rates. Sometimes you can rotate the MAF in the duct 90 degrees and make a 10% or more change in fuel trims.

Ron_Stoppable

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Yeah its running like ****. Like it keeps puttering like its running out of fuel with about 30% throttle applied. The finish on the throttlebody feels real rough like a shitty port job was attempted. Not sure if that would cause it .Should I just get a speed density tune? Its really annoying. I triple checked everything. What I dont understand is why am I getting code P0102 when the wiree are pumping out the correct voltage???

Old Geezer

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071/074..............Fuel pressure is???

Ed Wright

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So, you are getting P0102 also?

Ron_Stoppable

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Yup im getting P0102. I checked the voltage on the wires after it threw that dtc and its still reading correctly.
Fuel pressure is 60 psi at idle

Ron_Stoppable

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Just drove with the maf unplugged. I stepped on it and it coughed real bad. I wonder if I should swap to the larger set of flex fuel injectors I have laying around.....

Ron_Stoppable

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Changed the intake gaskets today. Its a noticeable difference in how smoother the idle is with them. Its still throwing P0102 and P0101 though. I checked hose clamps and vac lines... there is a bend in the intake rifht after the MAF before the throttle body.. where can I get an OEM maf sensor? A GM brand.