more air in means that there is more fuel burned to make the a/f ratio match again.

 

If you have 2 o2 sensors, gut your cat. Then the second 02 sensor will always read rich and your PCM will cut back on the fuel.I have that and I get 14+ MPG (with 24# injectors mind you). Bad thing is i am running lean

 

Running lean isn't a good idea, it creates way too much heat.

 

all i did to mine was go with a cat back and i only get all around 12 13 thats 5.2 auto running 245 want to step up to 285 and 3 inchs of lift

 

what is the deth flash ???

 

the death flash is a factory way of shutting ppl up. It was created to stop pininging compliaints....it makes your timing slow and really kills your lowend power i had it untill i retuned it with my superchips

 

Rather than recall the trucks to fix the plenum gasket problem, they reflashed the computers to retard the timing. Kills mileage and power, but eliminates pinging caused by blown plenum gaskets.

 

Thanks for all the replies. I have checked plenum and btw I do have a hypertech tuner.

 

And the 02 sensors are brand new when I did the magnaflow cat a couple weeks ago.

 

welcome to a dodge truck. i get 10 mpg.