I just had my check engine light go on in my 1998 civic and then at Autozone they plugged in their gadget and found out my civic had a bad O2 sensor. I then discovered that there are not one, but two O2 sensors. The Autozone manager said that we should replace the one closest to the engine first and then test it... he said that 90% of the time that one goes bad due to the heat of the engine. We did that and the engine now runs well.
It can actually be multiple things on a. Typically, it will be your primary O2 sensor, your fuel filter being clogged, or the fuel pump not supplying enough fuel to get the job done. Also, contrary to what another answer had said, the O2 sensors are NOT in series. The front (primary) O2 is used to fine tune adjustments and the rear (secondary) O2 is used simply to verify the catalytic converter is doing its job.
their is more than one oxygen sensor but the one that is probly bad is on the exhaust system. otherwise I would check the map sensor.
The oxygen sensor is one of many things that could turn the check engine light on.The oxygen sensor is one of many things that could turn the check engine light on.
possible abs or vvs speed sensor you need to check codes and go from there
Check for exhaust leaks, check O2 sensor functionality, replace catalyst.
check for tune-up, check maf sensor, check o2 sensors, do a fuel system service.
There is not one sensor. All the ECM sensors are tied to the check engine light.
That is what the check engine light is for. It informs you of a failure.
* It could be a faulty check engine light or a light sensor problem . There's probably not a problem with the engine at all just the faulty sensor light problem most likely. * ----------------------------------------------------------------------------------------------------If your check engine light stays on with the engine running , a malfunction with the emission control system has been detected. Have your vehicle scanned for any trouble codes in order to diagnose and repair the problem. ( I had a check engine light come on at 35000 miles - in my case it turned out to be the DPFE sensor )
The check engine light error code PO172 means that the system is too rich. The reason why the system is to rich is due to the mass air flow sensor being dirty or faulty.
Check Engine ... self explanatory ... check the engine. Check fluids, air filter, water in the coolant system, oxygen sensor, bad spark plugs, electrical problems, loose nut behind the steering wheel - could be any number of things ... check everything in the engine area.
If it is bad the check engine light will come on and set a code for that particular sensor.
Yes, an unplugged sensor can cause a check engine light.
There are sensors all over the engine that can turn the check engine light on.
NO. That means the engine is running too hot. Check cooling system.
Have system scanned if check engine light is on. I would check for vacuum leak and if none were found do a tune-up if due. May need a fuel system check ,,,,fuel regulator, fuel injector, fuel filter. Could be throttle position sensor or crankshaft position sensor. Could be a computer problem.
replace the bad sensor and it will turn off.
i have check engine light on code po171 system to lean i changed o2 sensor check engine light came back soon after, i heard that it could be fuel air ratio sensor,where is it located on 6cyl Toyota sienna, do you have any input thanks tony
How can I check the ENGINE COOLANT TEMPERATURE (ECT) sensor on my 1991 HONDA PRELUDE SI 2.1L
if you disconnect the o2 sensor cable in the air intake then start the engine you would see the check engine sign turned on in the gauge panel. It is on then the sensor is working if off the the sensor may have problems
The check engine light will come on anytime the ECU detects a problem with the emission system. It should also come on when you start the vehicle and stay for a few seconds and then go out.
fuel system check engine light on was diagnose as being the fuel sensor now car cuts off while driving What would be the problems? You think maybe the fuel sensor could be bad? It's nice when the check engine light gives you the answer
The O2 sensor is one of many things that can turn on the check engine light. You need to have it checked for codes.
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.
your knock sensor could need to be replaced
Is your check engine light on ? If it is then have the engine scanned with an engine scanner. Black smoke means engine/fuel system is to rich./to much fuel. Could be the MAP sensor,Fuel pressure regulator, coolant sensor. You need to scan the engine.