The Honda H23A2 is a 2,259 cc, inline‑four petrol engine produced between 1998 and 2001. It features a single overhead camshaft (SOHC), 16‑valve valvetrain and programmed fuel injection (PGM‑FI). This engine was designed for refined, torquey performance in Honda's premium models, producing 110 kW (150 PS) and 211 Nm of torque, offering smooth and responsive driving characteristics.
Fitted primarily to the sixth‑generation Honda Accord (CF chassis) Type R and the second‑generation Honda Prelude (BB chassis) Type S, the H23A2 was engineered for spirited driving while maintaining daily usability. Emissions compliance for its production period was met through its electronic fuel injection and catalytic converter, aligning with Euro 2 standards.
One documented concern involves the exhaust manifold, where thermal cycling can lead to cracking between the runners. This issue, referenced in Honda Service Bulletin 99‑018, is common in high-performance applications. Later H‑series engines saw revisions to the manifold casting for improved durability.
Production years 1998–2001 meet Euro 2 standards as per applicable EU regulations for vehicles of that era (VCA UK Type Approval #VCA/EMS/6792).
The Honda H23A2 is a 2,259 cc inline‑four petrol engine engineered for premium compact coupes and sedans (1998-2001). It combines SOHC 16-valve architecture with programmed fuel injection to deliver high torque and responsive performance. Designed to meet Euro 2 emissions standards, it balances sporty character with refined operation.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,259 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, SOHC, 16‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 86.0 mm × 97.0 mm | |
| Power output | 110 kW (150 PS) @ 6,000 rpm | |
| Torque | 211 Nm @ 5,000 rpm | |
| Fuel system | Programmed Fuel Injection (PGM‑FI) | |
| Emissions standard | Euro 2 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Belt-driven | |
| Oil type | API SJ/SL, SAE 5W-30 or 10W-30 | |
| Dry weight | 138 kg |
The high 10.0:1 compression ratio provides strong torque and responsive power but requires premium unleaded fuel (95 RON minimum). Strict 100,000 km timing belt replacement is critical to prevent catastrophic engine damage, as it is an interference design. The exhaust manifold is prone to cracking under spirited driving; listen for ticking noises. Using the specified 5W-30 or 10W-30 oil ensures proper lubrication. Fuel injectors may require cleaning after 120,000 km to maintain optimal fuel trim.
Oil Specs: Requires API SJ/SL specification oil (Honda Owner's Manual, Accord CF Type R 1999). Viscosity grade depends on ambient temperature.
Emissions: Euro 2 certification applies to all 1998-2001 H23A2 models (VCA Type Approval #VCA/EMS/6792). No market-specific variations for this standard.
Power Ratings: Measured under SAE J1349 standards. Output is consistent across all markets for this model (Honda EPC Doc. H-H23A2-001).
Honda Workshop Manual (Accord CF, Sections 6, 10, 11)
Honda Owner's Manual (Accord CF Type R, 1999)
VCA Type Approval Database (VCA/EMS/6792)
The Honda H23A2 was used across Honda's CF platform with transverse mounting. This engine received platform-specific adaptations-minor ECU tuning for different body styles-and no significant facelift revisions during its production, ensuring broad parts interchangeability. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the engine block, just below the cylinder head and behind the alternator (Honda Workshop Manual, Section 6). The 8th VIN digit for H23A2-equipped vehicles is typically 'H'. Visually, it can be identified by its black plastic SOHC valve cover and the distributor mounted at the rear of the cylinder head. Critical differentiation from the H22A: The H23A2 has a larger displacement (2.3L vs 2.2L) and a different exhaust manifold casting. Service parts like the timing belt kit are generally compatible across all H23A2 applications but verify using the EPC.
The H23A2's primary reliability risk is exhaust manifold cracking due to thermal stress, with elevated incidence in spirited driving. Honda Service Bulletin 99-018 documents this as a common cause of exhaust leaks, while UK DVSA data shows emissions-related faults as a frequent MOT advisory for this generation. Adherence to proper warm-up/cool-down cycles and proactive manifold inspection make preventative maintenance critical.
Analysis derived from Honda technical bulletins (1998-2001) and UK DVSA failure statistics (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about HONDA H23A2.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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