The Honda Civic Si EP3 (also known as the SIR in some markets, 2002–2005) was the performance hatchback variant of the Civic, using the high-revving K20A3 engine. The 2003 Honda Civic Si (SIR EP3) factory service manual documents the specific K20 engine and transmission for this model year.
K20 Engine Service
The EP3 Si's K20A3 uses Honda's i-VTEC variable valve timing system and requires a specific valve clearance adjustment interval to maintain the factory power curve, documented in the factory manual along with the manual transmission's specific fluid specification.
What This Civic Si (SIR EP3) Manual Covers
- K20 engine — valve clearance adjustment, i-VTEC diagnostics
- Manual transmission fluid specification and service procedure
- Complete electrical diagrams for all trim levels
