How to check the harness of O2 sensors ans knock sensor?

[Ryan Heo]

Hi. I replaced O2 sensors and knock sensor a week ago to get rid of check engine light. However it is still light on. So I bought a Ohm measure(digital mutimeter) to check the harness of the sensors. How to check those things?Thanks.

[95prmax]

question did you reset the ecu????

[Ryan Heo]

Yes, I did two times but I came out again.Thanks.

[brianw]

What codes are currently showing?

[Ryan Heo]

The code is P0155.HO2 21 heater condition (heated oxygen sensor bank 2 sensor 1)Thanks.

[brianw]

Check the continunity of the wiring with a multimeter, you're generally just after a continunity check there... if you have the FSM you may be able to find an o2 diagnostic procedure in there somewhere. Bank 2 is the bank by the firewall...

[Ryan Heo]

I rewired the O2 sensor and I reset ECU.The CEL is gone now but I think it need to wait 2~3 days. If the CEL don't come back on 2~3 days later, at that time I will tell you I did. I will post the result 3 days later.Thanks.

[Ryan Heo]

Hi.I think the CEL is gone surely now.The gas mileage is increased from 16 miles per gal. to 22 miles per gal.Acutally it is amazing. I recognized now that the O2 sensors are so powerful. However I still don't know how to check the sensors.In addition the car is hard to start sometimes even thought I did seafoam two times. Anyway if you guys have CEL, you had better to replace O2 sensors.Thanks.

[95prmax]

Hi.I think the CEL is gone surely now.The gas mileage is increased from 16 miles per gal. to 22 miles per gal.Acutally it is amazing. I recognized now that the O2 sensors are so powerful. However I still don't know how to check the sensors.In addition the car is hard to start sometimes even thought I did seafoam two times. Anyway if you guys have CEL, you had better to replace O2 sensors.Thanks.

its not necessarily that the o2 sensors are powerful but the problem is that when they go bad the ecu cant tell if the car is running to lean or rich so to counter act that it retards the timing by a lot making you loose power and waste more gas.......thats why its good to replace them...

as far as the ahrd to start is it in a cold start or everytime even after you just rant he car and its warm

[Ryan Heo]

Hard to starting is not in the cold condition. It doesn't have any unique condition. I think it just after I drove the car, but not everytime.once every ten I think. I replaced also a knock sensor, so I don't know what I do more.
Modified by Ryan Heo at 8:36 PM 7/9/2007