My friends 2012 ram 1500 w/ 5.7l has something weird going on where he keeps getting a cel for air-fuel imbalance and poor mpg. The dealer has charged him $100.00s for diagnostics (even though the truck is still under power-train warranty, w/ 56k miles) with no real answer. First, they wanted to charge him $600.00 to replace the spark-plugs. He did that himself (he is a certified dealer class-B mechanic) That is when he noticed oil & soot on the #8 spark-plugs only. Now the dealer wants to charge him $350.00 for a fuel system cleaning. It seems like they are just guessing. any ideas what we should look at first before they try to wrangle him into paying ? ( other than going to a different dealer, obviously )

 

Sorry folks. I posted this in the wrong forum section. Can a moderator move it where it belongs please ? Thanks. Mottman.