Hello forum! I am seeking help with my Truck, my theory is I have a problem with idle AFR, but i am no where near sure.
I will try to give as much information as possible to be of the most help. please for give me ahead of time, i am not a pro mechanic.
i am trying to solve a idle/cruising misfire problem ( misfire clears up at higher rpms) on my:
2009 gmc sierra sle 1500, 5.3 (vin M) 4x4 (299k KM)
before work was done on truck had Engine light (not sure of code) but warnings were: service trailer brake, service air bag. Lifters and cam died, decided to go with a full AFM delete kit.
the following work was done to the truck:
Truck Norris NSR cam install. including ls7 lifters, lifter trays, spark plugs,oil AFM delete oil plugs, heads re finished, valves cleaned. ect. (package purchased from Michigan motor sports.
Bench tuned PCM.
after receiving truck back from shop. there was lots of vibration. (assumed was cam chop). there was a loss of vacuum to the brakes. stalling when stopping to change gear(making 3 point turn) and was even sent into limp mode a few times. sent it back to the shop, And sent pcm back to bench tuner and traded in for a new pcm.
replaced brake booster, and installed vac can, new pcm installed. braking improved slightly. (not satisfied)
used cheap ODB reader to scan codes, got a code for oil pressure sending switch, i replaced it with a new one (and filter)
after about 500-700 kms driven, Engine light started flashing rapidly, acceleration decreased, sounded like a popping noise, like a detonation, that you can feel in the pedal. also a sluggish grinding feeling when accelerating from a stop, or low speeds.
took truck to transmission shop ( i feared for the worst) they told me trans(6l80e) is working perfect, but engine has a bad misfire.
so i replaced my spark wires with NGK wires. and coil packs with an oem option from local parts store. (still misfire)
my Hp tuners Finally arrived across the boarder and i did a dtc read.
pulled codes :
0x541: U0137 (pending, current, history)
0x543: C0299 (history)
0x543: C0561 (history)
0x7E8: P0102 (pending , old)
0x 7E8: P0113 (pending, old)
I purchased a new MAF sensor and replaced that, also cleaned air intake, throttle body with throttle body cleaner spray
cleared codes. and still none have come back. but Engine code remains.
i tested my 3 catalytic converters with a laser temp gun, and a 3-4 minute cold start test showed they were staying much cooler than the rest of the exhaust pipes/ manifold.
my misfire still is there in cylinder 7 and also some misfires in all the other cylinders. I have swapped coil and wire with cylinders 5-7 and the misfire is consistent with cylinder 7. I will replace the fuel injector in cyl 7 and see if that works.
i will attach my log and config, hopefully something sticks out of place for a trained eye? thanks in advance for any guidance!
newtuneupdatelogmms.hpl2009 Sierra 5.3 MM Mail Order Tune Anthony Agostino email tune update (2).hpt