BMW G20/G22 M340i/M440i Gen 3 B58 Downpipe

Take your B58 Gen 3-powered M340i or M440i to the next level with a high-performance catless or sport catted downpipe. This upgrade offers dramatic gains in turbo spool, power, and sound by removing restrictive factory emissions components.

⚙️ Product Specs:

• Engine Compatibility:
  ✅ B58 Gen 3 / B58B30M2 (2023+)
  ✅ Designed for G20 M340i & G22 M440i
  ✅ Works with both xDrive and RWD variants

• Downpipe Options:

  • Catless (Race Use Only) – Maximum flow, aggressive sound

  • High-Flow 200 Cell Sport Cat – Emissions-friendlier option

• Material & Build:

  • 📏 3.5” Diameter primary pipe, tapering to fit OEM exhaust flange

  • 🔩 304 Stainless Steel or optional Titanium

  • CNC machined flanges, TIG welded

  • V-band connection for leak-free install

🔥 Performance Gains:

• Up to +30 HP / +40 TQ with tune

• Quicker turbo spool and enhanced throttle response

• Aggressive exhaust note, turbo whooshes, and pops

• Works great with bootmod3, MHD, or JB4 tunes

🛠️ Installation & Notes:

• ✅ Bolt-on fitment — no modifications needed

• ⚠️ Check Engine Light (CEL) may occur without tune on catless version

• ECU tuning highly recommended for best results

📦 What’s in the Box:

• 1x B58 GEN 3 Downpipe

• Mounting hardware (may vary by manufacturer)

Want me to help you pick between catless vs catted, or pair this with a cat-back system, intake, or tune for a full-stage setup? Just let me know what kind of driving or sound you’re going for!