Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

02 senor

hey team,i have a 1998 ford taurus v6.the service engine light came on.i had it scan,and it said do i go about checking this out.i don’t want to just start adding parts.p.s can you damage a moter with a bad 02-senor.

The output of the oxygen sensor can actually be read with a scope. A meter too, some say, but I like graphics. I want to see a trace of the signal going up and down. I like pretty pictures.

Maybe you can damage a motor with a bad oxygen sensor. 1996 and newer vehicles have two sensors per exhaust header pipe. The “upstream” sensor(s) (before the converter) send(s) a signal to the ECU to help it properly meter fuel. The “downstream” sensor(s) (past the cat converter(s) send(s) a signal to the ECU just for comparison purposes to see if the converter is doing its thing.

Improper fuel metering can cause operating problems. Since you’re basing this on ECU fault codes, I’m going to assume that it’s referring to the upstream sensor. Often if the downstream sensor provides a bad reading the ECU will suggest a possible bad converter.

In summary, if the upstream sensor is bad it can cause operating problems. If the downstream sensor is bad it’ll simply cause a fault codes that tells you to check more carefully for a possible bad converter.

This car has 4 oxygen sensors, one upstream sensor and one downstream sensor for each bank of cylinders. The code should be able to pinpoint the correct one. The upstream sensors are required to adjust the fuel trim to keep from burning too rich or too lean. These conditions can damage the engine. The downstream sensors are to monitor the emissions only, and will not damage the engine if they fail.