if i add crawford HFC to my set up will i be running lean and need a tune??..anyone with any experience on this?..thanks!

 

more than likely you will. thats every possible basic bolt on. get a dyno w/ an A/F ratio reading and that should let you know

 

OEM WIDE OPEN THROTTLE is tuned very very rich to keep catalytic convertors from melting during long WOT conditions [greater than the few minutes it takes to get to 150 mph in summer heat AC on.

All external bolt on can do it at best increase power by 10-12% thus they would lean by 10-12%..............oem software would still be rich enough prior to cats to avoid melt down under these conditions.............assumming you are using conventional gasoline...........ethanolized fuel might be more problematic........depends on water content.........but lower btu should be self protective.

 

IMO you're probably slightly lean already and the cats will elevate that condition. I'd dyno and get an A/F before spending money on cats.