I have a 2001 <nobr style="font-weight: normal; font-size: 100%; color: darkgreen;" id="itxt_nobr_0_0">Silverado</nobr> 2500HD with a 6.0 liter. My check engine light will blink when in tow haul mode go off and then come back on. You turn off the tow haul mode and it will quit. I keep getting a PO300 misfire code. I replaced plugs, wires, Fuel filter. That didn't help. So I took it to a gut that told me I had 2 injectors that where bad. Replaced them and that didn't help. Just recently it started to to hold at about 2500rpm before it would shift from 2nd to 3rd. Then the check engine light would start to blink again. once it would shift it goes off. What is my problem? Are they related?

 

if its a misfire then check your coil packs. since its an 01 it should have a coil pack per cylinder. one of them might have gone bad. as far as the other issue. im not sure good luck