Colton Campo

Thanks for the quick reply man. Yes, I have the replacement lines. The O2 sensors were tracking but the passenger side pegged out with the misfire. My first thought was the sensor. Checked resistance and changed just for the hell of it. The incomplete burn makes a lot of sense with all of the carbon and sludge build up.

This will be my first post, but I've always use the site as a valuable resource. Thank you for that Vehicle is 2014 GMC Sierra 6.2l The truck sat at the dealership for 3 months and my problem still exist. The problem- multiple misfire, fuel trims all over the place . Parts replaced(all gm direct replacement)- (dealer suggested) -new transmission, new cat converter. Cost 8k (Self installed) -plugs, wires, MAF sensor, all O2 sensors. Thermostat Where I'm at now. Picked up my vehicle for the 3rd time from the dealership. Dealership said swaped wires and misfire cleared. Suggested a near air box and MAF sensor. Quoted @ $750 . Went and brought the vehicle home to work on it myself. Pulled left (passenger side) fuel rail. Misfire was indicated number 4 cylinder. The last injector "pocket" looked to have orange fluid pooled at the bottom. Got the injector out to find it full of "coking" and it was wet. Coolant is orange and the reservoir has seem to have lost some level. Pictures attached My question- What's my next move ? Did the injector have a seal problem? Clean and install new injectors ( already have them on hand) ? Dig deeper and replace head gasket?