P0306 NO MATTER WHAT I DO

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swathdiver

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2008 tahoe 5.3l. Wife was driving and went to take off from a red light and truck stalled. She got it running and the cel was flashing then on constant, and the service stabilitrak and traction control came on. She limped it home and I got a P0306 code. Did plugs and wires and still P0306. Swapped the coil pack to a different cylinder and still P0306. Changed the fuel injector still p0306. Took off the valve cover off cause it was a mix between a knock and a tick that you clearly can hear what cylinder it was coming from. Saw cylinder 6 valves were not able to move and the rocker arm wasn't touching it. Read that's a common issue with the AFM. Pulled the head and got another 1 from O'Reillys. Got everything back together and guess what still p0306 and still running like crap. Very rough idle, no power, not as bad a sound but can still hear a small tick. Ran a compression test and psi ranges from 125psi to 150 psi. Cyl 6 coil pack has power and ground, cyl 6 has a brand new fuel injector. Also when I pull cyl 6 spark plug it smells like fuel and is a bit wet. I am at a complete loss for what to do next. Can someone please help me.
Nick, make sure you replace the lifter trays with GM OE only. The counterfeit Chicom ones are out of tolerance and destroy engines immediately.

If your budget does not allow for a BTR Truck Torque or Truck Norris Camshaft, get the L33 camshaft from GM, 12583623. It is the same grind as your original without AFM. Not tuning required other than to turn off AFM.
 
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Nickct203

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So finally done. Got everything back together, started it up and sounds like crap lol. Not the same crap as before, just different crap. Oo, I did not do the afm delete kit, I went with just the stock afm kit cause my wife wanted her truck the way it was. But anyway, Im not getting the P0306 anymore. Its now a P0300. When I took the spark plug wire off cylinder 2 the metal piece inside stayed on the plug. I tried to put it back In the boot but I don't think it's right. I'm going to go see if I can buy just 1 wire instead of the set. I'll follow up after.
 
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Nickct203

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If it was just one wire, that would just have the code for that cylinder.
You are correct. I had a frustrated moment and wasn't thinking straight. P0300 is a multiple misfire. I think the intake manifold gaskets that came with the kit are absolute garbage. The location holes broke as soon as I tightened the 10mm head bolts. After looking at where it's sitting under there manifold, it doesn't look right. I went and got a mahle set and hopefully that will work.
 
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Nickct203

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At 3am I finally threw in the towel as it started raining. I got the new intake manifold gasket on. A friend was helping me for a little bit putting everything together earlier, apparently not only was the gasket set I had crap but numb nuts also broke a freak manifold bolt in the head. I got it out and chased the threads with a Tap. I don't ever suggest anyone buy the metal gaskets that go over the smaller head bolts, they are garbage. I got the 1 that snaps onto the intake manifold itself. Anyway my wife came out to help me get everything back on. I go to put the alternator on and never knew she already connected the battery. I arced the red power wire for the alternator on the alternator, now I have to juice what so ever to the truck. I checked and don't see any blown fuses anywhere. I think I might of cooked the battery. Put my charger/jump box on it and still no juice getting to anything. My multimeter was reading from 12v down to 4v and it just kept going up and down like a music scale. Anyone have any suggestions other than never have anyone help me again?
 

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