Generally, the onboard diagnostics will tell you when you scan the computer codes.
the check engine light will come on
Replace both of them.
An oxygen sensor is bad when it is no longer performing inside a set of parameters that are designated and optimal. The oxygen operates in a very narrow window of voltage and provides feedback to the engine to adjust the air/fuel ratio to maintain performance and emissions. If the sensor is bad and returning poor data, the performance, emissions and mileage will suffer.
When the oxygen sensor goes bad, the check engine light goes on.
Engine check light comes on, and you have the codes read.
The check engine light would come on.
Go to the auto parts store and buy a scanner OBD1 or OBD2 and it will let you know why your check engine light is on and if the o2 sensor is bad
When an oxygen sensor goes bad a car will burn gas at a higher than normal rate because it will not be producing as much power as before. The oxygen sensor checks the amount of exhaust.
Stop by your local AutoZone. They will hook it up to a handheld tester and print out which oxygen sensor is failing.
bad idle and chec engine light comes on. this can be checked with and obd 1 code reader
An auto xray scanner can determine if a O2 sensor is bad.
It sure can.