2001 Honda Accord 2.3L 5 Speed manual, LX. A few weeks ago my check engine light came on, I ran the code it said "Bank 1 O2 sensor confirmed" and "bank 2 O2 sensor current." I replaced the bank 1 O2 sensor and the check engine light went away. The car never ran different when the check engine light came on. Yesterday I was accelerating onto the highway and suddenly the car started missing and hesitating and it ran rough the rest of the way home (15 miles) missing whenever I would try to accelerate at all. The check engine light also came on at this time. I pulled the spark plugs and replaced them, the were all white with a white powdery substance on them, they did not look great. The car runs only slightly better but still misses whenever I accelerate or try to go up a hill. The check engine light gave me an error for misfire on every cylinder as well as the same message I had seen before "bank 1 O2 sensor confirmed, bank 2 O2 sensor current." So now I am curious, could it be some other problem (like a coil) that is causing the misfire's which then dirty's up the O2 sensor and causes it to fail or something? One other thing to mention: the car has missed before, but usually it was just for a moment and then it would be fine. Also sometimes when I would start it, if I let go of the key too soon (before it fully started) the car would stall and then it was difficult to start for a moment and I'd have to rev it up a bit to clear it out a bit.

 

What were the actual trouble code number(s)?

 

P0135 and P0155 (those were listed as the O2 sensor ones according the advance auto OBDII reader), and then also P0301,302,303,304 (cylinder misfires).

 

P0155 - There is no P0155 applicable to the 4 cylinders, as there is no bank 2.

P0135 is Primary O2 sensor heater circuit malfunction.

It is likely referring to the same primary O2 sensor.

The misfires are probably unrelated to the O2 sensor.

There is probably some other underlying cause such as faulty ECM, wiring, etc.

 

Thanks for the input. I was figuring the P0155 was referring to the downstream sensor but what you said makes sense, thanks for correcting that. When the check engine light came on the first time (P0135) the car did not misfire, drove totally the same. However, this time around it does misfire. The misfiring caused the check engine light to start flashing, then it would go off, and now it just stays on. So I'm not sure when the P0135 came on, but it was after it started running poorly. If there is some other underlying issue, why would the O2 sensor fault at the same time the misfires happened (or soon thereafter)? They must be related in some way right? But too your point, yes I don't want to replace the O2 sensor if that is the not the core issue. Any suggestions as too how to dig into it some more to see what the issue is? I guess I could drive the car with the OBDII set up and running and get it to misfire and see what it does?

 

i would try finding another ecu

 

What brand of O2 sensor did you use?

Good luck,
Sam

 

Problem solved: It was just spark plug cable wires. Switched them out and car drives like a champ now. Thanks for all the help. O2 sensor issue went away a few days ago even before I replaced the cables. I guess if the car misfires really bad or has bad combustion (due to weak spark) it can set off the O2 sensor for some reason.

 

thanks for the update