P0420 Honda

P0420 Honda

Honda has issued a service bulletin to address a Honda code P0420 Catalyst system efficiency below threshold on 1996-00 Honda Civic DX, LX, EX vehicles. The bulletin also addresses Honda cod P0301 Number 1 cylinder misfire detected, Honda code P0302 Number 2 cylinder misfire detected, P0303 Number 3 cylinder misfire detected, P0304 Number 4 cylinder misfire detected.

Honda has determined that the cause of the misfires may be poor connections at the igniter terminals. Start by crimping the wires from the distributor subassembly. Then clear the Honda codes and drive the vehicle. If the P0420 Catalyst system efficiency below threshold returns, you must replace the catalytic converter.

Exhaust manifold catalytic converter

Honda lists these part numbers for replacements

Manifold Converter (1996–98 Models): P/N 18160-P2E-A12, H/C 6146294

Exhaust Manifold Gasket (1996–00 DX/LX): P/N 18115-P2A-003, H/C 4838793

Exhaust Pipe Gasket: P/N 18212-SF4-000, H/C 2691681

Exhaust Flexible Gasket (Except EX & Si): P/N 18229-S01-XO1, H/C 4802500

Exhaust Flexible Gasket (EX): P/N 18229-S01-X11, H/C 4802518

Pre-Chamber Gasket (EX): P/N 18393-SH3-S00, H/C 3228806

Manifold Converter (1999–00 Models DX/LX): P/N 18160-P2E-A22, H/C 6149611

Converter (AEE360) (1996–98 EX Models): P/N 18160-P2R-A50, H/C 4810412

Converter (EX Model): P/N 18160-P2P-A00, H/C 5999420

Distributor Housing (1996–98 Models): P/N 30105-P2E-A01, H/C 4789467

Distributor Housing (1999–00 Models): P/N 30105-P2E-A12, H/C 8006371

Distributor O-Ring: P/N 30110-PA1-732, H/C 1126457

©, 2015 Rick Muscoplat

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