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Flowmaster Exhaust Systems Part #817664 Customer Reviews

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28 Customer Reviews


Reviewed by Eddy B (BONNER, MT) Reviewed for a 2014 Toyota Tundra — Feb 13, 2018 11:12 AM

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Install was simple I am a mechanic sounds great have only drove 20 miles since install would recommend buy

I would rate 10 stars for the flowmaster

Reviewed by Chau T (Worcester, MA) Reviewed for a 2016 Toyota Tundra — Aug 21, 2017 10:12 PM

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I just love the sound of it i shut my radio so i can enjoying the sound... and the price is unreal compair to the trd exhaust system i love it and thank you flowmaster

Great sound.

Reviewed by Mario R (FEDERAL WAY, WA) Reviewed for a 2013 Toyota Tundra — Feb 21, 2017 9:09 PM

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Exactly what I wanted, customer service was a great help.

Flowmaster American Thunder 2017 Tundra 5.7

Reviewed by Adam S (Chesapeake, VA) Reviewed for a 2017 Toyota Tundra — Feb 05, 2017 2:34 PM

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I bought the American Thunder system it sounded great outside but the drone at 1600-1700 rpm in the cab was to bad for me,I swapped out the original 40 series muffler that came with the kit with a super 40 delta flow series and it sounds 100 times better just as loud outside the cab with a much deeper tone and no interior drone what so ever, I got such a good deal on the kit I didn't mind buying the super 40. Would buy again.

Typical FlowMaster quality!

Reviewed by Andy E (MANDEVILLE, LA) Reviewed for a 2015 Toyota Tundra — Jan 03, 2017 9:51 AM

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I received this as a Christmas gift and was thrilled. The packaging was a big box and was flawless. Even the fasteners came in individual heavy ziploc bags. Installation was a breeze. (I have a 6" lift and did it in my driveway.) Everything fit and lined up perfectly - with just a few minor adjustments before tightening everything in place. Sounds and looks great.

Awesome system

Reviewed by Scott A (Slinger, WI) Reviewed for a 2017 Toyota Tundra — Dec 21, 2016 2:47 PM

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Sounds great, at a fair price compared to a standard system.

For a 2014 Tundara Crewmax

Reviewed by Brett H (Granbury, TX) Reviewed for a 2014 Toyota Tundra — Jul 08, 2016 8:53 PM

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It's OK but not as Racy as I wished. Should have gone with the Outlaw system with the black tips. I was worried trepid about committing to the loudness of the Outlaw, but after getting the American Thunder system , and watching YouTube videos with my truck having the Outlaw I wished U had chosen otherwise. Having said that, I would rate the quality of service from Auto Anthingvthrough the roof. In most cases my orders come the very next day having been shipped from San Diego. With free shipping!

Super 40 Drone @60 mph (Tundra 5.7)

Reviewed by Roland G (Baton Rouge, LA) Reviewed for a 2014 Toyota Tundra — Mar 17, 2016 1:55 AM

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Great exhaust. Sounds AWESOME. Pros: Growls when started, Quiet at idle, rumbles when you get on it. Cons: low tone DRONE at 1800 rpm which puts mph at 60mph. cruising speed.


Reviewed by John K (KISSIMMEE, FL) Reviewed for a 2014 Toyota Tundra — Mar 05, 2016 10:48 AM

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I have had flowmaster for years on all my sports car and now my truck. The American Thunder series is awesome. Just the right amount of rumble and a few extra horse power. And it's not to loud in the cab which I was worried about in the beginning but it's perfect. If your just cruising you hear just a small amount of the nice rumble but when you get on it it's fantastic the deep and aggressive rumble you hear coming out of the truck. Now my truck sounds like a truck should. Recommended it !!!

Installed on a 2014 Toyota Tundra 4.6

Reviewed by Edward F (Seguin, TX) — Feb 23, 2016 4:24 PM

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This exhaust souns and looks great. My one issue is the nuts and bolts to hold the chrome tips on were way to small. I hope this was a slip up in packing the parts. I installed this in about an hour in the parking lot were my Wife works. It was her 60th birthday gift. She came home from work smiling from ear to ear. Great system, I highly recommend it!

Flowmaster Exhaust Systems - 817664

Cat Back Exhaust - American Thunder Series
  • $836.96
  • Free Shipping
  • Ships Between 8/20 - 8/22
  • What Do You Drive?


  • Style:
    Dual Rear or Side Exit (409 Stainless)
  • Material:
    With Dual Exhaust Tips
  • Part #:
  • Main piping diameter: 2.5"
  • 40 Series Big Block Muffler
  • Includes dual 3.5" exhaust tips
  • Includes exit pipes for dual rear or dual side exit
  • Download installation instructions (PDF)

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