I have a 2011 Chevy 2500hd with 6.0. The truck has developed a misfire at idle and partially on the gas. I have replaced all the spark plugs, all 8 injectors, moved coil packs around, replaced MAF, MAP, b1s1 02 sensor (was getting codes for that sensor only), ECU, fresh gas and added cleaners, cleaned throttle body and swapped throttle body, had cats removed (already were blown out and empty) Nothing has solved the issue. Only bank 1 is misfiring. Mainly cyl 1 and 3. The truck backfires out the exhaust, and under load back fires out the intake. It will clear up like a switch flipped and run fine until the truck is shut off and restarted. I’m at a complete loss. By watching the snap on scanner. It appears as if it’s richen bank 1 and lean bank 2. I’m at a complete loss. It’s happening at idle and slightly off idle until it decides to clear up. I have been getting codes for random misfire and bank 1 sensor 1 02 sensor for heater issue. Sent from my iPhone using Tapatalk