adding cats to pass emissions
the cats a lot of work to do, and long tubes at idle helps none. A
high flow cat is less effective than a stocker even if you could keep
it decently hot, which you won't.
Yeah, you probably have to do it. But I'd expect some grief. At idle
and cruise the high flow cats won't bother the tune much if at all.
Other tricks are change the oil right before, SeaFoam the intake
(oil doesn't burn well and leaves a lot of HC out the back) and come
in hot when the guy is ready, don't sit in line cooling off the cats.
And you might look for the "right guy", not take any old joker and
expect them to cut you a break.




