At high rpm, about 4.5K-5Kish i get what sounds like rapid backfiring sounds like its coming from underneath the vehicle rather than out of the exhaust. other than that it seems fine. The previous owner apparently did some mods to the engine. it has a K&N intake, bosch plat +4 plugs and a flow master exhaust. seems to have the factory MAF still installed. dealer said that putting the factory air box back on will fix the prob but others have told me the converters may be gummed. since ive had the vehicle i havent done anything to mod it and normal everyday driving not even a ping. using
89oct. fuel. anyone experience similar or might know a cheaper fix? Thanks for any info provided.99 Z71 K1500
5.3L extended cab