2001 Mazda Protege 1.6 check engine light is on. Getting a problem code P1170. What does that code mean and what do I need to do? Please help

 

The code means that your front oxygen sensor is not switching correctly and has been either in the full rich or full lean conditon for almost a full minute which is not a normal condition. There is a link below to a TSB from Mazda for this problem that requires a reprogramming of your engine computer. This may or may not fix the problem. If the sensor is truly registering no changes in the fuel mixture then this will not work. Could be a faulty sensor or a problem with the engine such as a vacuum leak or leaking injector. Not an easy code to diagnose as it is rather ambiguous and could mean a lot of different things. The code simply means that your engine fuel mixture is not cycling from rich to lean condition like it should. Your engine is not going to explode if that is what you are concerned about, just a fuel mixture control problem.

 

[>:] Is there any test I can perform in order to diagnose the problem?

 

You could watch the front oxygen sensor output voltagewith a digital voltmeter is about the only check that you could perform cdelee. The front O2 is the sensor mounted in the exhaust manifold. Wire to backprobe with a volt meter would be Pink with Blue stripe. With engine warmed up the voltage at this wire should be fluctuating between in100mV to 900mV range. 450mV is the median range, anything below that is a lean exhaust and anything above is a rich exhaust.The voltage reading should cycle from rich to lean about once every second at idle and even faster with engine rpm raised. If the voltage is stayingbelow 450mV which would be lean then give a quick squirt of carb cleaner into the PCV valve. Voltage should instantly jump to 800-900 milivolts. Same with staying above 450mV but create aquick vacuum leakby removing a vacuum line.If the O2 responds quickly to these changes then it is probably ok and you would then need to determine why the engine is staying too lean or too rich. There are codes that will be set if a rich or lean limit is reached due to a vaccum leak or some other problem but they can sometimes take quite a while to develop that far.