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
Posted on by Rick Muscoplat