Will the X-pipe without cats bolt up to the stock manifolds if you don't want to use headers and will you still see power gains? Anyone running without cats on the street, any problems?

 

I have the JBA L/T off road headers on mine, havent run "cats" in about 1 year. No problems here, unless you count my neighbors being upset in the mornings when I start it.

 

Hey aagvain - does the Mac system have the connections for the O2 sensors? Did you have to re-flash or have any CHECK ENGINE problems?? And did it make quite and improvement on the overall sound? I've always had MAC in my old 5.0 days so I am thinking of going with this pipe over the winter.

 

it has the connectors. i'm pretty happy with it. didnt have any install issues. i did have to reflash though. it triggered the cel. my tuner turned off the rear o2 sensors which took care of that.

 

The factory exhaust pipes are 2 1/2? (correct)? Do you really notice that much of a change going with a aftermarket x-pipe? I just bought my 05 GT last week and I have on order the elinor kit with the side exhaust. The mufflers are from magnaflow. If I bought a off road system I would still run cats so I'm thinking just by replacing the x-pipe without doing your cats it won't make much of a diiferences?