I was wondering if anyone has an opinion or knowledge on this. the muffler shop guy told me the 5.0 would need a tune no matter what because the 02s, the front ones wouldn't be able to read the higher volume of exhaust gas and as he put it, he couldn't put them in the exact location as factory. a tune shop agreed but why wouldn't they...its money for them. I talked to a shop that sends people to another shop for dyno tuning but he said its, in his opinion, wasted money because the setup the way it is may have a bad wire I cant find or a querky sensor that could be screwing with 02s . he did say the one advantage to the tune would be the guy could make the ecu ignore the cat 02s but he wants $70 for an hour with my truck and his laptop to see if he can find something wrong. the thing I can find is b4 the headers I had one code for both banks running rich...now after driving a day to work it will show up to 4 codes...bank 1 sensor 2 has bad connection or fault, bank 1 and 2 front sensors slow response. and 02 switch shows rich. I drive it to work and back..about 34 miles then I disconnect battery for 10 minutes and it fine...deleting the codes with scanner doesn't help so I do the battery thing. at times she will idle slightly rough then hit gas and she is fine, other times she idles so smooth I don't know its running. any thoughts on this would be appreciated. lol, a parts guy at work said he woulda put a carb n distributor on it...I like it efi but every sensor gotta be right on