im getting better mileage with my cats cut off of my truck, but the check engine light is on... will it hurt it to just keep driving like that? i thought when the check engine light came on the mileage starting dropping... now im completely confused...

 

Its in a default mode...I guess it won't "hurt" anything,but its not going to run its best...plus,you won't know if you really do get a problem

 

Agreed^^. You should get a custom tune to get rid of the ses light. Programs it out and you can make more power. I suggest getting a 160 degree thermostat first. This way, they can adjust your timing even further to makeeven MORE power.

 

yeah a custom tune is next on my list, i just dont have the cash for it right now, i just wanted to make sure i wasn't about to destroy anything driving it like that... thanks for the help

 

Other than the descreen, have you done any more of the free mods???

 

here ya go..... https://www.truckforums.com/m_11160/tm.htm

 

thats the only one i've done so far, but im planning on doing the throttle body bypass pretty soon