DynomaxUltra Flo 17554 Exhaust Muffler

sounds great on my 4.6 GM, kinda like a mustang sound, i kept my cats so it's not very loud until you really get on it. i thought it would be way louder. it's definitely not super quiet but it is nice sounding, it almost pops like a glasspack when u really get up past 4000 RPM. has a nice low, mellow rumble without almost no drone. i love it. way better sounding than my 40 series flowmaster. i like loud pipes so if u want a super quiet muffler this isn't for you.

I used the DynoMax Ultra Flo™ X, model 17554, dual 3" in, dual 3" out Muffler to replace a restrictive factory mid-muffler. The Muffler benefits include reduced restriction, compact size compared to the factory mufflers in my case, and added scavenging with the built-in cross flow X-Pipe that helps create better exhaust gas evacuation through the venturi effect. In my exhaust system, the product was slightly louder than stock . This was all of the features I was looking for. I was very happy.Unfortunately, the product failed within a month and would have failed sooner if not for low driving miles. The product internals began to rattle, fall apart, then it blew out the fiberglass sound absorption material through the downstream piping and mufflers with possible restriction in the other mufflers from debris. I tried a second replacement muffler from the same manufacturer within a month. I find it unlikely that two muffler failures were caused by a rare failure anomaly and more likely that the product has a design defect, most likely bad welds, poor material strength, or material heat tolerance. Hopefully the manufacturer will solve this quickly. Very disappointing.

UPDATE: After 1k miles the sound has improved in the muffler. Still missing a fully rounded sound. But it has gotten better.Overall, my muffler did not suffer any build quality issues like other reviewers. Although the muffler does it's job, it is very quiet on my truck. I have a 8.1L big block and the muffler doesn't sound much louder than stock.Bottom line: I would not recommend this muffler to friends, and if i knew the sound would be quiet I would not have purchased.

The media could not be loaded. Sounds great! Has the perfect low rumble that sounds mean and tuff. At highways speeds it's super quiet so no drone at all, but when you get on the gas it provides that mean sound I want.I heard this muffler compared to Flomaster and Flomaster sounds more like a hot rod muffler that when you let off the gas makes that wap wap sound. This muffler sounds more like a truck muffler. Sounds great when you first take off at a light all the way through the first 3 gears easily. If you want a little more back pressure and torque for towing go with the dual in and the single out. I put this on my Chevy 2500HD with the 6.0 and sounds perfect.

I installed this muffler on my 2006 silverado 2500HD. The muffler appears to be well reconstructed and seems to be a superior design compared to the flowmaster super 50 that I replaced. It's got a nice straight through design and it sounds great. I would definitely recommend it if you are looking for a nice growl without a ton of drone on the freeway. Definitely not a quiet muffler on my truck though.

This muffler was in service less than one year and the bottom blew out. Not from rust, but from poor material thickness or quality. My truck is no powerhouse 4.8 ls with headers, so it is not excessive horsepower that caused the failure. Just general poor quality.

I wanted more sound from my 2003 Silverado SS without redoing the tailpipe or going with a cat back system.I did quite a bit of research before finding this muffler. All I had to do was cut the old muffler out and weld this one in its place. The SS has a dual in dual out muffler on it stock so this Dynomax fit the spot perfect. And I kept my original tail pipe and stainless steel tip which I did not want to do away with.This muffler has a great sound at start up, not too loud cruising and pretty loud when you get on it. Also has a small decal pop when you let off.Hey I didn't turn on my radio or stereo for a week after I put it on so I could enjoy the exhaust tunes.

I bought this muffler for my LS sandcar that makes 400 HP. I thought for the price it would be a high quality muffler, stainless and all. I am a welder by trade and i cant figure out this stainless that is fully magnetic. It gave a real nice sound and within the first 5 hours it began to crack around the end cap welds. I weld repaired the crack. Within the next 6 hours the spot welds on the can sides began to crack thru. I could not repair without pulling the muffler apart. Return time was up. I kept running it and then the crack and hole formed what are shown in the picture. I believe i am supposed to have a lifetime warranty. The manufacturer has not responded so buyer beware.