i have an 06 ram 1500 3.7 with auto trans.
Truck has about 107,000 miles and seems to run ok. I keep getting misfire codes from cylinder 4 and cant quite seem to pinpoint the problem without taking it somewhere to have it diagnosed. The codes being pulled are P0300 random misfire, P0304 Misfire cylinder 4, and P1128 A few mechanics said its either the compression, fuel injector, coil or spark plug. I have changed the plug and coil about a year ago and figured i could rule out the compression because it would be a constant misfire if the compression was off. I should add that its an intermitent misfire and doesnt happen all the time. usually happens if the truck is sitting at idle after it has sat for a few hours or misfires and hesitates when i try to accelerate after sitting for a few hours but after it misfires it seems to run fine. I have a new plug and bought a fuel injector but wanted to get some advice or tips from you guys. I also was wondering if you guys had any tips for improving gas mileage on the 3.7. I have stock exhaust and no engine mods but did move to a 265/70/17 tire size which doesnt help but i didnt like the 245's. Thanks for your help guys.