inline4

On pin

<U>"D14-PHO2S O2 sensor White, heated 02 sensor Signal, 0.4-0.5V when ignition is turned on; drops to less than 0.1V within 2 minutes"</U>

I tested it with a multimeter in a hope to fix my code 1 which does not want to go away. I bought a new o2 sensor and it still won't go away.

I get a constant .435 volts no matter how long the car idles or drives. It's suppose to drop below .1v

Anyone know why this is happening?

P.S. Car is a 92 VX hatch with b20b and p75 ECU p75 engine harness 4 wire o2 sensor everything obd1

singlestic

Are you testing at the ECU? Have you tested the signal wire at the O2 sensor plug.
It should constanly switch from high to low as it goes rich to lean. Low voltage is lean and high is rich. .45 volts represents stoichiometric. Your primary should fluctuate and if you had a secondary it would stay steady once the vehicle was at operating temp.

singlestic

Your Vx has what is called a LAF sensor (Lean air fuel) originally. It is a Ion generator not an oxygen sensor.

inline4

i'll try to test it at the o2 sensor, but i was testing it at the ecu originally.

inline4

ok i spliced into the white signal wire at the o2 and got no voltage reading at all.
then spliced into the harness side for the signal wire and still got no reading.

any ideas?

inline4

they say that all 92-95 civics are prewire from the shock towers for 4 wire o2 sensors but i'm not too sure about that....

when i look at the ecu pinouts and diagrams the colors for the wires are all wrong too. i get org/blue when its suppose to be green/yellow, etc.

inline4

bump cause i fixed it! i will post the answer for all 92-95 Civic VX owners with swaps in the civic forums.. Not ALL 92-95 Civic VX's are prewired for 4 wire o2s from the shock towers.

inline4

the fix https://honda-tech.com/zerothread?id=1513794