Just yesterday i started up the car, and began driving down the m4. I noticed that instead of the car sounding a nice clean: "baaab" sound, it was more of a "faaaf" sound... Hard to explain sorry, a kind of a more muffled sound that usual... It also seems sluggish, especially when changing into second...

I have:
-Pacemaker Extractors
-Hi-flow cat
-2.5 inch pipe from the cat back
-sports muffler

Any ideas what this could be? It does not sound healthy and i dont want anything that could ruin my engine... so i want to fix it ASAP....

Thanks
James...