if i take off my cats do i need to re tune?

 

Probably not. I took mine off and there wasn't much difference in the tune. If your still running a MAF then you should be fine.

 

You don't have to but I did anyway. Allen told me it would run a little richer and he shut the rear O2s off in the tune so I would not have to buy sims or ger SES light coming on.
If you have to pay for the retune I would say no, but if you have a Nelson tune its part of the "Tune for as long as you have the truck aggrement"
You just don't want to abuse the man, he's very busy but always willing to help.

 

allen retuned his truck after cutting out the cats and got 35-40hp more outta it if i remember right....

 

That alone is a great reason for a re-tune IMO.

 

ok thanks alot guyz

 

I would reccomend a re-tune.. Your rear sensors are suppose to read leaner than the front due to the cat removing the excess fuel.. If you dont re-tune, your rear O2s will be reading the same as the fronts, and therefore think the engine is running to rich and try to lean it out..