yourboysoap

I’m troubleshooting an o2 sensor P0141 code after a transmission swap. I’ve replaced both o2 sensors at this point which got rid of the first code but the o2 sensor heater circuit bank 1 sensor 2 won’t go away. After some research, it looks like I may have made the common mistake of plugging these in backwards and frying my PCM. Ill confirm that for sure but my stupid simple question is, do I just unplug both sensors and plug them in the other way? Like sensor 1 plugged in where 2 currently is and 2 where 1 is? Want to make sure I get this right before I get my spare ECU reprogrammed.

flanders

The only way to switch these connectors up is plugging in ECU<->ECU and O2 sensor <-> O2 sensor.
Switching back both to ECU<->O2 sensor should be enough yes.

yourboysoap

why the hell did honda do it this way? why not have different connectors? i cant believe how many people have done this (myself included) and burned up their ECU because this is like, the only place on the car where connectors can be plugged in to the wrong places.

flanders

If it was the same connector for both O2 sensors and you switched up front and rear instead, it could be even worse and engine is damaged instead of just ECU?
Just speculating

Cossa

I used a cheap rear O2 sensor off eBay and it threw a P0141. This resolved itself with the Denso rear O2 sensor.

yourboysoap

I replaced both my sensors with Densos but off the reading ive done for other people with this issue and how quick it throws the code after i reset it (literally seconds), im pretty sure that's what it is.

yourboysoap

I think one way it works properly, the other way shorts the ECU heater circuit.

yourboysoap

wanted to bump this once more before i swap the connectors for the o2 sensors and get honda to reprogram the ECU:

Did I fry my ECU O2 heater circuit because I plugged the #1 o2 sensor in at #2 and plugged the #2 sensor at 1? Or is there some other wiring I messed up? would love to be sure before i fry my only spare ecu

flanders

Only you can tell us how and what you have connected where. It is indeed a good idea to check this before you connect a new ecu.

Billman250

That can’t be done. You can however plug the two o2 receptacle plugs into each other. Even this cant be done unless the receptacles are removed from their mounts. Which is not necessary when replacing o2 sensors.