Just wondering about the quality of a magnaflow catback exhaust on a 2007 Sierra 5.3L. Also have heard that when it kicks back to 4 cylinders some exhausts out there sound bad.

 

I won't try another exhaust on my '07 crew until I can hear it first. Some folks here say they cannot hear the AFM change from 8 to 4 cylinder with the stock exhaust. I sure can without looking at the DIC. After driving it for a while you will notice it. I tried a Dynomax dual, installed it on a Saturday and pulled it back off Friday afterwork. I couldn't wait to get it off. I traded from an '04 ExtCab with the 5.3. I wish I had that set up in this truck, the mileage was no different. Probably due to the heavier weight. But it seemed to pull alot harder...

 

Wow finally someone noticed it. The others said they cant notice the difference. That is what I suggested about the cylinder deactivation, but I guess you gotta have good hearing cuz I sure as heck would notice it.

 

I had the Dynomax on the '04 and it was fine, loved it. I want the good flow out the back but not too loud. Dynomax is on the low cost end of the choices for the pre-AFM engines. The first time the wife and daughter got into my '07 SLT heading to Chilies' was the final straw. When the cylinders dropped off to 4 both of them said, "what is that sound"? and off it came.. Of course I knew it was coming three days into it. I was told to look at Corsa, the first thing I noticed is they cost about twice as much but if they sound great it would be worth it.