I had all sensors replaced in my 03 Trailblazer and the check engine light stiil comes on. Why?
Your O2 sensor is a "part that is designed to wear out". there is no standard on replacing them, but if your car is running fine, and your check engine light comes on, and stays on, it's probably an O2 sensor.
Check engine light will come on for various reasons. The o2 sensors could be one of them. If your belt breaks the light will come on and the engine will over heat. I mentioned the o2 sensor because when it comes on for this reason some people have had that light on for years without replacing the sensor.
Maybe, the check engine light comes on when the computer detects a malfunction and sets a code.Maybe, the check engine light comes on when the computer detects a malfunction and sets a code.
There is a failure in the oxygen sensor heater.
Normally, the light on means the oxygen sensor (s) need replacing. As for the smell, be more specific.
the sensor is going out
check the crank sensor
The check engine light for the 2001 Isuzu Rodeo often comes on because of a sensor that is damaged or malfunctioning. The most common sensor is an oxygen sensor and when reset, this often allows the light to be reset.
You need to test/replace the knock sensor. ireplaced it already.
Without pulling codes, I would quess the Oxygen sensor is weak and needs replacing.
Engine check light comes on, and you have the codes read.
If check engine soon comes on it means you may have a computer sensor telling you something is wrong. You should get a code readout ASAP. Mine let me down and it was a mass air flow sensor the problem.