Aftermarket muffler affecting power?

[m4yh3m]

Not long after purchasing my 2000 Silverado, I had a Flow Master muffler installed. Fast forward 9 years... I've always had problems with trying to "get on it" and go from a stand still in traffic -- the engine will rev, RPMs will zip up to 2000 or so, but the truck will crawl until the RPMs lower and then it'll start moving. Mind you, this is a v6 engine pushing a 4 door truck, so I'm not expecting to boil my tires when I get on the gas. However, it can be a hassle when trying to get into traffic and people are already hauling ass, and I periodically don't get the get up and go like I can when enabling the tow/haul. Back to my main point -- is it possible that I have the wrong kind of muffler on my truck and it's not providing proper back pressure needed by the engine? What kind of muffler would be recommended for a v6?

Secondary question: Would it be worth my while to throw roller rockers arms in my engine to get a little more efficiency out of it?

[99'HEARTBEAT]

Boy thats a tough one,Do you know what Series Flowmaster you Have.

[vncj96]

Do you have a stock air box, while you are not gonna get noticable power form a CAI but you WILL get the RPMs to climb quicker when you need them too, like when passing on the highway. But most likely its your rear end that is holding you back the most, differnet gears would help, and being that you have V6 in a four door truck you probably dont get the greatest mileage anyway so it shouldnt be a bother to lose a bit, even a programmer could help a bit to decrease some of the engine management

[grimreapersshadow]

tuneup? done in there somewhere maby get an hushpower from flowmaster

[omegafiler]

I guess the question is did you actually notice the loss in power after the muffler was installed?

Unless the muffler is way too small or too large, it shouldn't cause a problem. You could take a look at it and see if the inlet/outlet pipes are much different than the factory stuff.

And if you want to rule it out, just run to an exhaust shop to have them check it out. Or even put a real muffler on there such as a Magnaflow.

This is of course in addition to check all of the usual stuff. Check for any codes, give it a tune up, etc. Just make sure everything is working OK. It could just be that the stock engine isn't giving you the kind of power you need/want.

[m4yh3m]

I appreciate the varying responses covering some different aspects which I will look into.

No idea what model the flowmaster is... had it installed not too long after I purchased my vehicle (can't believe its been 9 years). This is just something that I've noticed for a while.. and being more geek than gear, I passed it off as a normal function of the newer vehicle (had an old 87 silverado with a 5.7 and would boil the tires if you barely touched the pedal). But the exhaust is primarily the only major "surgery" performed on the truck, and I started getting curious as to just why in the hell it would rev the rpm up when I gassed it, but would lower back down to near idle and then "catch" and start moving. Damn if I don't love my tow/haul button for the sheer reason that it shifts hard and I don't have to worry about sputtering up when trying to jump into crazy traffic.

Surprisingly, I get very good gas mileage. I can get 18 or so, and with it having a lower gear, push it to 80 MPH and sit at 2k RPM -- my girls Escape does 60 @ 2k RPM with her v6, and while that get up and go is nice, I'm not a fan of seeing it drink so much.