Flowmaster 40 Series Chambered Muffler
- 3.00 inch center inlet, dual 2.50 inch outlets
- Aggressive sound from the 40 Series chambers
- 16-gauge aluminized steel, oval case
- Universal fit for cars, trucks and SUVs
- 10.1 pounds, 20 x 10 x 5 inches
Last refreshed Oct 2, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A loud chambered muffler with a single large inlet that splits to two outlets, for muscle cars, street rods, trucks and SUVs. It needs matching pipe sizes and a dual tail pipe layout.
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ASIN: B000182DO2Model: 430402Category: Mufflers
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Overview
Flowmaster builds this muffler with a center inlet and dual outlets in an oval aluminized steel case. It is the original chambered design, sold as universal fit and tuned for an aggressive sound.
A single inlet feeding two outlets suits systems that end in dual tail pipes, and the chambered body gives a deep tone. Buyers must match the inlet size and layout themselves, since no vehicle list is given.
Who it's for
Suited to performance builds that run a single pipe in and dual pipes out where loud is the point. A daily driver wanting low drone, or a car with a single outlet layout, needs a different design.
Pros and cons
- Single inlet splits to dual outlets
- Original chambered design
- Aluminized steel construction
- Universal fit part
- Sound is aggressive, not mild
- Warranty terms not stated
- Needs dual tail pipe layout
Performance notes
Exhaust enters through the center inlet, passes through the internal chambers and divides to leave through two outlets. The chambers cancel part of the sound and create the deep tone, and the oval case sets the ground clearance needed.
Where it stands among mufflers
- #2 most-searched brand and model of the 15 mufflers lines we track (by search demand, not sales).
From the specs of the 15 mufflers we list; not a test result.
Specifications
| Brand | Flowmaster |
|---|---|
| Model | 430402 |
| Dimensions & fit | |
| Inlet size | 3.00 inches |
| Item dimensions | 20 x 10 x 5 inches |
| Weight | 10.1 pounds |
| Construction & materials | |
| Material | Alloy Steel |
| Compatibility & installation | |
| Vehicle type | Car |
| Warranty & support | |
| Warranty | Check with the manufacturer |
| Other details | |
| Configuration | Center/Dual |
| Fit type | Universal Fit |
| Shape | Oval |
| Highlight | 16-gauge aluminized steel, aggressive sound |
Frequently asked questions
How do I care for the Flowmaster 430402 muffler?
The listing gives no care or maintenance instructions. The highlight describes 16-gauge aluminized steel, and the warranty field says check with the manufacturer.
What pipe sizes does the Flowmaster 430402 use?
The title gives a 3.00 inch center inlet and 2.50 inch dual outlets.
Is the Flowmaster 430402 vehicle specific?
No. The fit type is universal, so you match pipe size and layout yourself.