p0132 code, replaced sensor, CEL comes back on.
 

I have an 01 Civic EX (had it 19 years now and love it) and recently, the CEL came on and the car about stalled out while going up an incline. I read the code and it showed p0132 and that was it (no other codes). I've now had the upstream sensor replaced 3 times since (twice with Denso parts, then with a Honda factory part the dealership ordered for me). The car will drive a little better now (but a little sluggish), but the CEL will continue to come back on when it hits an incline (interstate exit ramps, to give you an idea). This has happened after each new sensor we tried.

I'll take it home, leave it off for an hour or so, and the code will go away on its own. I'll drive it again the next day and the CEL will come back on again, at inclines. It wont stall out anymore (but will feel a little sluggish), but the CEL coming back on again and again with the p0132 each time makes me think it might be more.

Since this problem started, I've also replaced the fuel pump and had a tune up. It's currently back in the shop and they're having trouble diagnosing it. They think maybe wiring harness, or a PCM issue.

Maybe a cat issue, or injector issue? Neither of those codes popped up, just the p0132, so idk. The fuel sluggishness is what gets me.

Anyway, any ideas/thoughts/experience with this would be great. Thanks everyone.

P0132 - O2 circuit high, sensor bank 1, sensor 1

Meaning is the O2 sensor Bank 1 Sensor 1 is the air to fuel ratio sensor
If the voltage is going high then it could mean the PCM is using this signal to reduce fuel to the cylinders
The fact that it happens when you go up an incline says that it is probably a wiring issue.
The thing is to trace where the wiring insulation is open and/or touching a hot wire.
Follow the upstream O2 sensor wires and trace back.
Check connector to make sure no pins are bent
Follow wire again and see if there is anything rubbing against the wires
I wish you good luck with this one.


Note: Leaky of clogged fuel injectors can also cause similar conditions which makes it diffcult diagnosis

So they diagnosed it as a bad PCM, along with a bad wiring harness. The connectors/pins at both the PCM and harness were pretty bad, along with a few other spots along the harness.

They can replace the PCM, but sadly, they said the harness has been discontinued and I haven't had any luck finding the part online.

Not sure what I'm gonna do yet, as of now.

Wiring can be fixed. Take it to an auto electric specialty shop and they can fix it.

Thanks for the reply grcauto, I'm gonna look around for shops.

Symptom of slowing down on inclines usually a sign of clogged catalytic converter. While going up hill the debris in the cat fall into a pile and block more of the cat.
Then while on level ground the rumbling will even thing out again. Hardly ever get a code for clogged cat???

PCM?? OMG?? Tell me how they came up with that one? Or were they just guessing because it is an expensive repair??
So far this shop has not been able to diagnose this issue and you still trust them??