Honda 2000 Accord SE 4cyl: P1149



Hi, I had the check engine light come on at around 110k and went to Auto Zone for their reading. It came back with a P1149 and they suggested I contact the dealer or look online because they could not find explanation of this error code in their books and did not know what the error code meant when they looked it up on the computer. The printout they gave me notes a possible "failed H02S" which they thought was the oxygen sensor but were not sure.

Upon researching this, it appears it can be an issue with the oxygen sensor or the on-board computer. Apparantly there is a Honda Technical Service Bulletin 01-031 issued on this subject for 98-00 Accords. I guess this would apply to my vehicle? I cannot find evidence of this TSB when I search for it on my vehicle over at Edmunds.

Any suggestions on how I could proceed? Looks like the repair discussed on 01-031 is not cheap and I would prefer to explore other alternatives if possible.


Nov 13, 2006
Oregon Coast
One thing to check on is your warranty.
If I am not mistaken, the ECM is covered under the emissions warranty and may still be under warranty. You will need to check with your dealer to confirm that.

DTC P1149: A/F Sensor (Sensor 1) Range/Performance Problem
DTC P1165: A/F Sensor (Sensor 1) Range/Performance Problem
NOTE: If some of the DTCs listed below are stored at the same time as DTC P1149 or P1165, troubleshoot those DTCs first, then troubleshoot DTC P1149 or P1165.
P0137, P0138: Secondary' HO(2)S (Sensor 2)
P0141: Secondary HO(2)S (sensor 2) Heater

Reset the ECM/PCM.
Start the engine. Hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on.
Test-drive under following conditions.
55 mph (89 km/h ) steady speed
A/T in D4 position (M/T in 5th gear)
Until the readiness code or Temporary DTC P1149 (P1165) comes on
Is Temporary DTC P 1149 (P1165) indicated ?
YES - Replace the Primary HO(2)S (Sensor 1).
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at C102 (located under the under-hood fuse/relay box), the primary HO(2)S relay, the primary HO(2)S (Sensor 1), and the ECM/PCM.
Check for a Temporary DTC with the scan tool.

April 17, 2001
Applies To:
1998-00 Accord L4 - ALL
MIL Comes On With DTC P1149
The MIL is on, and DTC P1149 (air/fuel ratio sensor range/performance problem) is set.
Under certain driving conditions, the ECM/PCM sets a false DTC P1149.
Replace the ECM/PCM.
Out of warranty:
Any repair performed after warranty expiration may be eligible for goodwill consideration by the District Service Manager or your Zone Office. You must request consideration, and get a decision, before starting work.
Connect the PGM Tester to the vehicle's DLC (data link connector), and check for DTCs.
^ If DTC P1149 is stored, go to REPAIR PROCEDURE.
^ If another DTC is stored, go to the appropriate troubleshooting procedure in the service manual.


Great help, thank you. I contacted Honda and was informed the warranty expired at 80k/8 years. I guess I will proceed by taking it into the dealer for them to do their diagnostic on it, unless there is anything else I can do prior. As it stands, the check engine light is off (due to being reset by Auto Zone) and has not yet come back on. I suspect it will come back on soon?


Makes sense. Plus if taking to the dealer and the light is off, I will be questioned as to why the light is off, etc. I was thinking should I attempt to reset the ECM? How would I go about doing this?