Hi everyone new dodge owner and to fourm board. Bought my 2006 dodge ram2500 5.7 4x4. 4 days after buying tranny goes out! Guy bought from screwed me over. Finally got enough money for full rebuild. Was told cats were stopped up real bad. Engine light kept staying on with and blowing black smoke out the back. Mpg would go fromto 16 17 to 6-8 within minuets after removed positive batt cable, and dumping all my fuel. Couldnt afford to drive broke down again and Replaced with high flow cats flowmasers and duals out the back. Same issue with smoke and dumping fuel. P0139, p0159, p0171 codes showing now any ideas?

 

Sounds like the original owner drove this one hard, put it away wet and didn't do a lick of maintenance. All too common I'm afraid.

1st off, why would you put on hi-flow cats and then use about the single most restrictive, chambered mufflers on the planet? Seems counter productive to me.

Code P0139 is slow response from the Bank 1, Position 2 sensor (driver's side, after the cat).
Code P0159 is same thing on the passenger side.
Code PO171 is a too lean code.

The good thing is they are all probably related. A leak in the exhaust system can account for ALL three issues, so I'd start there. Either at the exhaust manifold or your welding has a lot to be desired at those new cats...