2005 mustang GT. Mostly stock. Offroad X pipe w/ Flowmasters.

Lately, it seems that my car sounds extremely "chuggy" when in high gear/low RPM. If I'm in third at 1.5 - 2.5 RPMs, I have a pretty nasty chug/chop. Sound like an exhuaust leak perhaps?

 

Did you just put the o/r X on or have you had it on and just now hearing the sound..?

 

It was on when I bought the car. Had it overa year. Perhaps I'm being paranoid as my warranty is almost up.