cat back exhaust and Active Fuel Management
 

Has anyone confirmed that there is a negative effect on an engine that has a catback exhaust when it cuts back to four cylinders?

RE: cat back exhaust and Active Fuel Management
 

I'd would like to know the real answer to this too, I've seen them for sale on the lot brand new lifted and with exhuast on them, so whats reallygoing on here?

RE: cat back exhaust and Active Fuel Management
 

a kid in town has some strait pipes on his 07 and it sounds good until it drops into 4 cylinders. for some reason it sounds like a V8 missing on a few cylinders

RE: cat back exhaust and Active Fuel Management
 

Performance wise you won't notice any issue using an aftermarket muffler when it switches to V4 mode. However, sound wise you will. IMO most of these systems make the trucks sound like a little civic with a fart can( term for a "ricer' performancemuffler in case you haven't heard it )when they go into V4. I hate it. Have heard a few different systems( Flowmaster, Magnaflow, etc... )and it sounds awful in V4.

Gibson and Corsa however both offer mufflers with their systems designed specifically to combat the V4 "drone". I have not heard either of those in person yet though.