Creed106

That's another weird thing I forgot to mention. It has never shown a specific cylinder misfiring, before ecm change all cylinders showed zero misfires and I would get a p0300 code. I don't know after ecm change my scanner won't show me these numbers. But yes everything points to passenger side, I have considered injectors, but it runs perfect at highway speed and full throttle.

Also the truck has new plugs and wires,oxygen sensors, ecm, 132k miles. 6.2L denali

Truck started missing at idle, p0152,p0157,p0300,p0430,p2099 codes( might have missed a couple it's been a bunch) found a tsb about the codes and changing the ecm, took to local dealer to have ecm changed they said it was valve springs, then they couldn't find a broken one so then they put a high pressure fuel pump on it. Same thing then they said it was ecm so they changed it. Get it back it runs good for about a week but keeps giving me a 2099 code, which after a few days changed to 430 and 157 codes. Started missing again yesterday. Any help would would be appreciated.