Ok so ive had this truck since i was 15, it has always been great the last year or two it has idled roughly and mpg has dropped despite the routine maintenance I have performed on it. It has began to (i believe possibly) pinging in between 3500-4000 rpm and after seafoaming it lightened slightly but still did it. I added seafoam to my oil and sucked it in through my booster cable. It gave me the notorious sea foam smoke and seemed to clean the engine out. After letting it set for 15 min as seafoam instructed I noticed some sort of leak between where the exhaust manifold bolts to the engine block. It seemed to have faulty gaskets. I researched the codes my superchip pulled up(po300,po304,po316) which made perfect sense after this long of trying to figure out what the heck is wrong with it. Apparently Ford put out a service bulletin on the 2004-2006 ranger with the 3.0 vulcan. Ford labeled it as exhaust valve seat recession and showed the exact error codes my ecu gave me. Is it possible that I have a leak and after seafoaming it cleaned out whatever helpful carbon build up which was not showing itself before? Has anyone else had this problem? What do i need to replace? If its just a gasket thats no problem.. ANY HELP IS NEEDED Please..

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Mods: 2" lift(torsion key and blocks),32/11.50 Kumho AT, Rancho Shocks, Hella Fog lights, k&n air filter, 5%tint all the way around, Black bed liner sprayed tool box, black headlights/tail lights, 15/8 Allied wheels, SuperChip Installed, Flowmaster 40 series perf. exhaust(single out behind passenger door),BlackHorse Bull Bar, top end rebuilt.