Collection: 2004.5-2005 Duramax LLY Exhaust Systems

6.6L Duramax LLY Exhaust

Exhaust systems for the 2004.5–2005 GM 6.6L Duramax LLY. A larger-diameter system lowers exhaust gas temperatures and frees airflow as power climbs. Every part is matched to your truck and the rest of your build.

Exhaust

Downpipe-back and turbo-back exhaust in aluminized and stainless. Larger-diameter exhaust lowers EGT and frees airflow as power climbs.

Compatibility

Organized by confirmed fitment for the 2004.5–2005 GM 6.6L Duramax LLY.

FAQ

What's the difference between downpipe-back and turbo-back exhaust?
A downpipe-back replaces the exhaust from the downpipe rearward; a turbo-back also replaces the downpipe for the freest-flowing setup.

Aluminized or stainless steel?
Aluminized costs less and suits drier climates; stainless resists corrosion and lasts longer, especially where roads are salted.