97 2.3 oxygen sensor issue

[Tlee1214]

My ranger had a bad sensor two because the wires somehow rested on the drive shaft eating them away. So I replaced it, cleared the code, and it then gave me a code for sensor one. Replaced sensor one, cleared the code, and my check engine light still comes on the second time I start the engine after clearing the code so why is that? There is nothing else wrong as the only two codes given were for both the sensors, and it just says there still bad. (But clearly not since they're new)

Also after replacing them both, it was the third time I had driven it and it dogged down taking off from a stop sign so bad that it wouldn't pull itself. Did that for probably 30 seconds then was fine and hasn't done it sine.

Any thoughts would be appreciated thanks.

 

[RonD]

First what were the exact codes before and now?

Codes are usually set because sensors ARE working and detected a problem.
Obviously if wires are broken or shorted a non-communications code would come up, so not the usual Lean or Rich codes a working O2 sensor will detect.

O2 sensors are Heated, if there was a shorted wire then the Heater Fuse may have blown.
It would be in the engine compartment fuse box.

On Cold engine start, the computer runs in "Choke Mode"(open loop) so doesn't/can't use O2 sensors, as they need to be above 650degF to read Oxygen levels correctly, that's why they are heated, so they can warm up faster.
O2 sensors usually start being used after 5 minutes of warm up.
And while O2 sensors are used by the computer for feedback on Oxygen levels in the exhaust they can't cause stumbling like you described because they are just used to fine tune the air:fuel mix for best economy.
Bad O2 sensor could cause lower MPG(running rich) or engine might "ping/knock" when accelerating(running lean).

The MAF(mass air flow) sensor could cause that type of stumbling.
MAF sensor is the main sensor the computer relies on to set air:fuel mix, if it gets dirty computer is basing the fuel it is adding on the wrong air flow, that usually produces a Lean mix and code and can cause stumbling, lack of power and hesitation of the engine.

 

[Tlee1214]

Sure enough it was the HEGO fuse. Replaced it and everything is good now thank you RonD.

 

[RonD]

Good work