I have an off road x pipe I love, I did get the Check engine
light till I had the rear o2s turned off via a tune.
They make a off road h pipe that will replace your factory one, this way you don't have to cut anything and if you still have emissions or a warranty you can swap your factory h with cats back on
2007 Ford Mustang GT 5spd
Brenspeed tune, JLT 3, Hurst shifter, 4.10s
O/R Xpipe, 15x8 Jeg Stars with Micky Thompsons