I went with the true dual 40 series, nice aggresive tone and I could feel about 10hp in gains.
Could I replace the stock cats with a free flow model and not trip the check engine. Any help is appreciated.

 

cut off the 2 elbow cats and replace em with 2.5" mandrel pipe and if your stock converters are still good just use them til the get stopped up or somethin and if it runs rich or the light comes on put a 1/4 ohm resistor on the signal wire (gray wire) of the downstream o2 sensor and it'll fix it.