DTC P0131 - FRONT HO2S SENSOR 1 Honda Odyssey I

1. Perform PCM reset procedure. See «PCM RESET PROCEDURE/CLEARING CODES»(ref-16063-S24481449252001010800000). Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator fan comes on. Road test vehicle with transmission in "2" position (A/T) or 4th gear (M/T). Using scan tool, check HO2S (sensor 1) output voltage during acceleration to Wide Open Throttle (WOT).
2. If voltage does not stay at.1 volt or less, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires at HO2S (sensor 1) and PCM connectors. See «WIRING DIAGRAMS»(ref-16063-S09829279722001010800000) section. Repair as necessary. If voltage stays at.1 volt or less, check fuel pressure. See FUEL SYSTEM in «BASIC TESTING»(ref-16061) article. If fuel pressure is not within specification, repair fuel supply system as necessary. If fuel pressure is within specification, turn ignition off.
3. Disconnect HO2S (sensor 1) connector. Start engine and run at idle. Using scan tool, check HO2S (sensor 1) output voltage. If output voltage does not stay at.1 volt or less, replace HO2S (sensor 1). If voltage stays at.1 volt or less, turn ignition off. Disconnect PCM connector "D". see scheme 4
4. Measure resistance between ground and White/Red wire in HO2S harness connector. If continuity exists, repair short to ground in White/Red wire. If continuity does not exist, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.

Scheme 17

1. Perform PCM reset procedure. See «PCM RESET PROCEDURE/CLEARING CODES»(ref-16063-S24481449252001010800000). Start engine. Raise and hold engine speed at 3000 RPM with transmission in Park or Neutral, until radiator fan comes on. Road test vehicle with transmission in "2" position (A/T) or 4th gear (M/T). Using scan tool, check HO2S (sensor 1) output voltage during deceleration using completely closed throttle.
2. If voltage does not stay at one volt or more, system is functioning properly at this time. Failure is intermittent. Check for poor connections or loose wires at HO2S (sensor 1) and PCM connectors. See «WIRING DIAGRAMS»(ref-16063-S09829279722001010800000) section. Repair as necessary. If voltage stays at one volt or more, turn ignition off.
3. Disconnect HO2S (sensor 1) connector. Install jumper wire between HO2S harness connector terminals No. 1 and 2. (Scheme 17) Turn ignition on. Using scan tool, check HO2S (sensor 1) output voltage. If output voltage is not one volt or more, replace HO2S (sensor 1).
4. If output voltage is one volt or more, turn ignition off. Connect jumper wire between PCM connector terminals D7 and D11. Turn ignition on. Using scan tool, check HO2S output voltage.
5. If voltage is not one volt or more, repair open in HO2S (sensor 1) circuit between PCM harness connector and HO2S harness connector. See «WIRING DIAGRAMS»(ref-16063-S09829279722001010800000) section. If voltage is one volt or more, substitute a known-good PCM and recheck. If symptom or indication goes away, replace original PCM.