Griffdawg6969

Bosh 02s, going to swap for some desnos the readings in the scanner just look really erratic to me

Fuel pressure is solid, I’m going to try switching the injectors tomorrow with new o rings. It’s just weird that the truck falls on its face and sputters in closed loop but runs like top dog again in open loop

I’m starting this thread in desperate need for help, for starters I’m not a mechanic or anything but I do find myself very handy to fix whatever with basic diagnosis . I have a 2003 Silverado 2500 6.0 with a truck Norris cam, k&n cold air, no cats, long tube headers, with time , ls7 lifters, ls6 springs along with all new bearings and hi flow oil pump all done around 15k miles ago, the truck initially started with a hesitation around 3k rpm which then turned into a Missfire(p0300) I suspected it to be my spark plug wires as I used the oem style ones which contacted the header, so my first thought was to replace them for 45 degree wires, then the fuel pump went out, replaced pump and filter, aswell as regulator. I don’t remember exactly what cylinders it misfired on before the fuel related problems, but after the parts change it seemed to only hit on cylinder 1. I did notice that in Open loop either cold or with maf unplugged(truck throws a lean bank 2) the Missfire goes away. My stft are sitting pretty close to 0 for bank1 and around 4-5 for bank 2 Ltft are normal in bank 1, but bank 2s ltft sits around +17 at idle and goes to around 9 ish when on the gas. The alarming thing is after some tinkering with the truck the Missfire seems to move cylinders, now I’m primarily missing on cylinder 6 and sometimes 4. I’m thinking I could possibly have a problem with the pcm as when preforming an injector pulse test every injector seemed to drop the pressure by the same amount. I’ve tried everything new 02 sensors as it threw a code for both heater cores. ( they seem to be jumping around with data). I had even tried a crank relearn to no avail. I’m not sure what else I could possibly look into, could somone maybe give me some pointers this is driving me nuts