BMW M340i Exhaust: Axle-Back vs Cat-Back Comparison
Explore the differences between axle-back and cat-back BMW M340i exhaust systems, focusing on sound, drone, and daily usability for your vehicle.
By Lee Shahin ·
Exhaust Systems
Cat-back and axle-back systems, downpipes and the emissions rules that apply to them.
Performance parts by model
- BMW M340i downpipes (15)
- BMW M340i exhaust systems (69)
- BMW M4 downpipes (7)
- BMW M4 exhaust systems (81)
- BMW M3 downpipes (7)
- BMW M3 exhaust systems (81)
- BMW M2 downpipes (4)
- BMW M2 exhaust systems (62)
- 2015-2018 BMW M3 downpipes (11)
- 2015-2018 BMW M3 exhaust systems (66)
- 2015-2020 BMW M4 exhaust systems (61)
Start with these guides. Product recommendations within each article have their own disclosures. Confirm fitment against your vehicle and the retailer before ordering.