My cats recently decided to go out and now im looking into replacing them due to the fact that my wonderfull state is all emissions testing and they do check under your car. My question is it worth buying highflow cats, or from what i heard the mustangs have decent cats ont hem to just replace the stock ones and buy a xpipe. just tyring to get some views on this


1997 Mustang GT
Stock...


Brian

 

The aftermarket pipes have smaller, better flowing cats, but IMO they have a tendency to clog faster and be worse as far as emmisions. The one advantage is that you will see a better gain and have a better tone/sound from the aftermarket pipes.

If it were me, and I was worried about emissions, I would buy an O/R X pipe to drive around. Come time for inspections, put your stock one back on, get your sticker, then put the O/R one back on.

 

^ Great answer.

 

ok i could see that, but i was thinking of a set of BBK longtubes, some sort of cats, and a xpipe after them...

 

In that case, even though MAC LT's have smaller primaries (tubes that come off the chamber) they are easier to fit with a stock K-member and still allows easy access the the starter bolts. BBK's have bigger primaries, but are a PITA come time to drop the tranny.

For sound matching purposes a straight through muffler design would sound better with an x-pipe, but I have heard of "bastard" setups where people put blowmasters on X-pipes and still sound good.

 

true, but i have easy access to a lift and tranny jack and all that good stuff. Im trying to find the most power affordably...



1997 GT
stock...