2021-2025
2015-2020
2009-2014
2004-2008
1997-2003
Installation Time
(approx) 4 Hours
Difficulty Level:
Light to Moderate mechanical skill required.
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Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (98-03 4.6L F-150)Find parts that fit my vehicle
Item T533467
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253 Reviews
1 Answers
Our Price
$899.95 kit
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$299.00
Product Information
Features, Description, Reviews, Q&A, Specs & Installation
Features & Specs
- Superior Performance
- Stainless Steel Construction
- 2.50” Tailpipe
- 3.50” Polished Stainless Steel Tips
- Bolt-On
- Aggressive Sound Performance Tone
- Made In The USA
- Moderate-Level Installation
- Installation Time Is Approximately 1 Hour
- Limited Lifetime Warranty
- Fits all 1998-2003 4.6L Ford F-150 Models
| Brand | Flowmaster |
| Exhaust System Type | Cat-Back System |
| Exhaust Tip Finish | Chrome, Polished |
| Exhaust Tubing Diameter | 2.50 Inch |
| Exhaust Material | Stainless Steel |
| Exhaust Tip Outlet Style | Dual |
| Exhaust Exit Location | Both Sides or Rear - After Tire |
| Exhaust Loudness | Moderate |
Description
State-Of-The-Art Performance. The Flowmaster American Thunder Cat-Back Exhaust - Split Side/Rear Exit is the exhaust you want if you are looking for superior performance and durability. Built with stainless steel, this exhaust system is out-performing all others on the market.
Cutting-Edge Technology. With a 2.50” Tailpipe and 3.50” stainless steel tips, you will love the look this exhaust system gives your truck, not to mention the deep, throaty, aggressive sound it puts out.
Superior Engineering. Made in the USA, this bolt-on system will turn heads and be the envy of all after-market enthusiasts. If you want unrivaled quality as well as performance that packs a punch, the Flowmaster American Thunder Cat-Back Exhaust is the product for you!
Installation. Installation for this product is rated at a moderate level because you will either need a hoist or an extra set of hands. The installation time is approximately 4 hours.
Warranty. Flowmaster gives you a Limited Lifetime Warranty that will cover any defects or flaws in the materials or craftsmanship of this product.
Application. The Flowmaster American Thunder Cat-Back Exhaust - Split Side/Rear Exit fits all 1998-2003 4.6L Ford F-150 models.
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Flowmaster 817663
CA Residents: 
WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov
Installation & What's in the Box
Installation Info
What's in the Box
- (1) Extension Pipe
- (1) Inlet Pipe
- (1) Muffler
- (1) Right Tailpipe
- (1) Left Front Tailpipe
- (1) Left Rear Tailpipe
- (2) Side Exit Tailpipes, L/R
- (2) Stainless Tips
- Hardware Kit
4.6
Customer Reviews (253)
Review Summary
Installation Time: Afternoon
Aug 6, 2018
1998 - JodyH
Installation Time: Afternoon
Awesome
So I have a 98 f150 with 4.6 in it And I bought this because my friends told me they were a good exhaust and who boy are they good!!! I have new headers on my truck and then with these under my truck hard to would recommend it to anyone
Fit & Finish 5/5
Loudness (Volume) 5/5
Exhaust Note 5/5
Bang For Your Buck 5/5
Jan 8, 2019
Review shared from Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (98-03 5.4L F-150)
2001 XLT - RyanW
Installation Time: Afternoon
great sound
This was an easy install and it sounds great. i had no problems with the fitting.
Fit & Finish 5/5
Loudness (Volume) 5/5
Exhaust Note 3/5
Bang For Your Buck 4/5
Apr 11, 2025
Review shared from Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (21-25 5.0L F-150, Excluding Tremor)
2021 XLT -
Installation Time: Afternoon
American Thunder
It sounds amazing! However, it is louder than I expected inside the cab. If you are towing a load, it can certainly cause you to turn up the radio........ The wife is not a fan, but I love it.
Fit & Finish 5/5
Loudness (Volume) 3/5
Exhaust Note 5/5
Performance Gain 3/5
Bang For Your Buck 4/5
Feb 7, 2025
Review shared from Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (15-20 5.0L F-150)
2017 - Ethan1234568791
Installation Time: Afternoon
Solid Product
So far so good. I’ve had it on my F150 for about a week and everything seems to be doing fine. There is a pretty good amount of drone in the cab around 65-70 mph, but that was expected. Impressed so far. Install wasn’t terrible. Biggest pain was getting the clamps to bite down good to keep the pipes in place.
Fit & Finish 4/5
Loudness (Volume) 3/5
Exhaust Note 4/5
Performance Gain 1/5
Bang For Your Buck 4/5
Jan 1, 2025
Review shared from Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (04-08 5.4L F-150)
2006 XLT - BigAl23
Installation Time: Less than 1 Hour
East install great sound
Everything fit perfect. Has the sound I was looking for.
Fit & Finish 0/5
Loudness (Volume) 0/5
Exhaust Note 0/5
Performance Gain 0/5
Bang For Your Buck 0/5
Oct 31, 2024
Review shared from Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (15-20 5.0L F-150)
2018 XLT - Esmith1998
Installation Time: Less than 1 Hour
Loud
Sounds awesome when you’re into the throttle and even better in parking garages
Performance Gain 2/5
Fit & Finish 5/5
Loudness (Volume) 4/5
Exhaust Note 5/5
Bang For Your Buck 5/5
Oct 7, 2024
Review shared from Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (09-10 5.4L F-150, Excluding Raptor)
2010 Lariat - Charge
Installation Time: Shop Install
Great sound
Had a shop install with JBA shorties the appearance and sound is amazing.
Fit & Finish 5/5
Loudness (Volume) 5/5
Exhaust Note 5/5
Performance Gain 5/5
Bang For Your Buck 5/5
Oct 7, 2024
Review shared from Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (15-20 5.0L F-150)
2020 Platinum - limoman39
Good Buy
The Flowmaster American Thunder seems to have great quality, we will see how well it holds up before I actually comment on that. Everything fit and the install was pretty straight forward. I like the sound it makes although it might be a little loud for my taste. I'm getting used to it, if it is too annoying I'll go down to the 50 series muffler. The problem with the switch is that the 50 series is longer which will require shortening the front pipe. I am a little disappointed in the price, I think it's too high for what you get. All in all it was a good purchase for me. Thank you,
Fit & Finish 5/5
Loudness (Volume) 3/5
Exhaust Note 4/5
Performance Gain 0/5
Bang For Your Buck 3/5
Jul 22, 2024
Review shared from Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (21-25 5.0L F-150, Excluding Tremor)
2024 XLT - TedKerr
Flowmaster exhaust
The exhaust arrived in great condition. Installed in two hours. The installation was a breeze. The sound was what I wanted.
Fit & Finish 5/5
Loudness (Volume) 3/5
Exhaust Note 3/5
Performance Gain 0/5
Bang For Your Buck 4/5
Jul 4, 2024
Review shared from Flowmaster American Thunder Dual Exhaust System; Side/Rear Exit (15-20 5.0L F-150)
2018 XLT - Berto14
Installation Cost: 414
Installation Time: Shop Install
Sounds like pure freedom!
I have a 2018 f150 sport with the 5.0 and it sounds amazing! It honestly makes it sound like I have something bigger then a 5.0
Fit & Finish 0/5
Loudness (Volume) 4/5
Exhaust Note 0/5
Performance Gain 5/5
Bang For Your Buck 5/5
Questions & Answers (1)
Will It Fit My F-150
- 4.6L V8 - 98, 99, 00, 01, 02, 03
