OKTAN
BMW S58 Downpipe
$699.00
Made to order — ships in 10–14 days
Fits your vehicle
Check fitment
Lower driver-side corner of the windscreen, the sticker in the driver’s door jamb, or your registration / insurance card. It’s 17 characters — we decode it instantly and never store it.
- Custom-made to order — ships in 10–14 days
- Free tracked shipping across the USA
- Secure payment
- Fitment guarantee — we confirm before you buy
Catless vs 200-cell — which configuration?
| Catless | 200-Cell High-Flow | |
|---|---|---|
| Airflow | Maximum | Excellent |
| Sound | Loudest, most aggressive | Aggressive, less raspy |
| Check-engine light | Needs a tune to clear | Usually code-free on a tune |
| Street & emissions | Off-road / competition only | Far more street-friendly |
| Best for | Track & max-power builds | Daily drivers wanting more |
Emissions & off-road notice. Catless configurations are sold for closed-course competition and off-road use only and are not legal for street use on pollution-controlled vehicles. You are responsible for compliance with the emissions laws where you drive. Prefer a street-friendly setup? Choose a 200-cell high-flow configuration above.
One S58 downpipe that fits them all. A direct bolt-on flow upgrade for the BMW S58, TIG-welded from mandrel-bent 3.5" / 89 mm T304 stainless and test-fitted in-house. Replaces the restrictive OEM catalyst for faster spool, a stronger note and the headroom your tune needs.
Fitment — BMW S58 (2021–present)
| Chassis | Models |
|---|---|
| G80 | M3 |
| G82 / G83 | M4 |
| G87 | M2 |
| F97 | X3 M |
| F98 | X4 M |
One downpipe fits every S58 car via the OEM mounting points.
Why owners choose OKTAN
- Faster spool & sharper throttle — less back-pressure, earlier boost.
- Deeper, more aggressive tone with no cabin drone at cruise.
- Unlocks your tune beyond the restrictive OEM catalyst.
- True bolt-on — no cutting or welding.
Specifications
- Material: T304 stainless steel
- Piping: 3.5" / 89 mm mandrel-bent, back-purged TIG welds
- Flange: CNC-machined V-band
- Flex section: braided stainless
- Configuration: catless (base) or 200-cell high-flow — choose above
- Sensors: OEM O2 positions retained
- Warranty: lifetime against manufacturing defects
Made to order, free tracked US shipping, dispatched in 10–14 days. Fitment confirmed before you buy.
T304 StainlessAerospace-grade steel — never budget mild steel
True Bolt-OnFits the OEM mid-pipe — no cutting or welding
Flow-TestedEngineered & test-fitted in-house on real cars
Lifetime WarrantyCovered against manufacturing defects
Install at a glance
IntermediateDIY difficulty
2–4 hoursTypical time
Basic hand toolsSocket set & ratchet
Ramps or liftRaise & support safely
- Let the exhaust cool fully, then raise and support the car on stands or ramps.
- Soak the fasteners and O2 sensors with penetrating oil before removal.
- Transfer your O2 sensors to the new pipe — OEM sensor positions are retained.
- Seat the flange and tighten the V-band clamp evenly, then torque to spec.
- Running catless? Pair it with a supporting tune to manage fuel trims and the CEL.
- Every order is fitment-confirmed before it ships — stuck? We’ll walk you through it.
Complete the install
Customer reviews
4.9
/ 5
Verified purchase
Fitment was perfect — lined up with the OEM mid-pipe in about three hours. Spool is noticeably quicker now.
Verified purchase
Paired it with a Stage 2 tune and the car pulls much harder up top. Worth every penny.
Verified purchase
Noticeable mid-range gains and a much more aggressive note. Took my time and it went in without issues.
Verified purchase
Massive difference in turbo response and the sound is exactly what I wanted. Bolted straight up with no check engine light.