| Author | Message | ||
     Adrian Lee (410225) New Member Username: 410225 Post Number: 4 Registered: 07-2003 |
I have 97 Disco I and check engine light was coming on. SO I brought to dealer and said Driver side front )s sensor is bad. I wanted second opinion. So I brought to independent Rover mechanic and he said, driver side back sensor was bad. And he asked if dealer was just going by the fault code. Now, how do you detect or check yourself if the O2 sensor is working or not? I do not know who to believe and do not want to change 2 O2 sensors if it is working. Thanks in advance. | ||
| patrick findlay (Montreal) New Member Username: Montreal Post Number: 22 Registered: 06-2003 |
did you ever get an answer? | ||
| Adrian Lee (410225) New Member Username: 410225 Post Number: 5 Registered: 07-2003 |
NO | ||
| Jeffrey DelVecchio (Jeffreydv) New Member Username: Jeffreydv Post Number: 37 Registered: 01-2003 |
Try this. O2 sensors generate small electrical charges when they are working. If you disconnect the sensor from the harness and connect the wires to a digital volt/ohm meter you should be able to detect fluctuating voltage when the engine is running. If you have a sensor that does not register or is different from the others then that is the bad one. Jeff | ||
| Peter Matusov (Pmatusov) Senior Member Username: Pmatusov Post Number: 953 Registered: 09-2002 |
Jeff, it's a three-wire sensor. 02 sensors do not generate any small electrical charges, you need to provide it with power and KNOW what signal to expect. Adrian, spend $122 on OBD-2 soft and hardware (from obd2.com), and you'll know more than you want about your O2 sensors. Just by saving yourself two trips to shops you'd be ahead of the game already (if you have a laptop or desktop that you can bring within 10 fr from your vehicle). | ||
| steve herrod (Sherrod) Member Username: Sherrod Post Number: 44 Registered: 02-2003 |
can your o2 sensors be bad and still pass the emission test done by the state? | ||
| Jeffrey DelVecchio (Jeffreydv) New Member Username: Jeffreydv Post Number: 39 Registered: 01-2003 |
Peter, Oxygen sensors do produce voltage. A three wire sensor is heated and therefore needs the extra wires to power the heater. The following quote is from the How It Works wegb page, this is also what I learned when I went to school to become a mechanic: "The oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures. The mechanism in most sensors involves a chemical reaction that generates a voltage (see the patents below for details). The engine's computer looks at the voltage to determine if the mixture is rich or lean, and adjusts the amount of fuel entering the engine accordingly." Jeff | ||
| Adrian Lee (410225) New Member Username: 410225 Post Number: 6 Registered: 07-2003 |
What size o2 sensor socket do I need to replace o2 sensors on my 97 Disco I? | ||
| Peter Matusov (Pmatusov) Senior Member Username: Pmatusov Post Number: 961 Registered: 09-2002 |
Steve - possible (if they don't trigger CEL) but not very likely. Jeff - I know that How It Works is a real authority, but it wouldn't hurt to see the good 02 sensor signal on the scope once, just to know what to expect. |
