Hello. I just bought my ‘04 and love it but am having a strange misfire. I will pull codes as soon as I can(obd2 plug not working). The truck has a steady engine light and a flashing check engine under load. I’ve poured through these threads and several people have had the same issue but have never posted a resolution. As the truck is new to me, I thought a tune up would be a good place to start. I installed new coil packs(factory LR) new spark plugs(Bosch) and new plug wires(Magnecore) as recommended on other posts. The misfire didn’t go away and has remained exactly the same. I’m not loosing any coolant. The old spark plugs had a bit of carbon and smelled of unburnt fuel but did not look steam cleaned. Another thing I will note. There does seem to be a higher crankcase pressure(not PCV, it’s clear) causing a leak in my rear main seal area(I’m sure it’s not coming from above)Any thoughts? I suppose you’ll ask me for the codes which I will get to you as soon as I can read them. Thank you

Stefan