92Protege
 

the 'check engine' was on suddenly during the driving when I turned at the traffic light and accelerated. I opened the hood and found nothing. This happened two times yesterday and today. Since I just changed oil recently, it should not be the cause. I am new on this mechanical work, anyone give me some suggestion to begin with? Thank you!

How many miles do you have? Could be a bad oxygen sensor

it's around 106K. I will check it with my manual since I even do not know what is oxygen sensor. I will try it. Thank you!

I am a newbie to autos. what is the ECU and how to check this. I will do some google on this. My mileage per gallon is around 20 at local, so I am wondering it is the oxygen sensor problem. The light on always on when I am on speed over 45. but when I turn off and then reignite the engine, it will be good for a while. several minutes later, once the speed is over 45, the light will be on again. when driving locally, sometime it will also lighted. Now I have some time and I try to fix this. Thanks a lot.

do the 02?????????

if you're doing 20 mpg there is something wrong, try to change the O2 sensor, there are not expensive and when you open the hood you'll see metal protector that has a hand (do not touch) and it says hot, there you'll see a wire in the down pipe that goes to the O2 sensor in the exhaust manifold or will be more easer if you go to a work shop and replace it.

I think you what you mean is buy the O2 sensor and replace by myself or ask the workshop(auto repairer) to replace it. I heard that the O2 sensor could be at the order of ~$200, if labor is added, woo.......
Thanks, I will try do my myself. what about the other one on the exhaust? I am told there are two O2 sensor. Thanks

Horn on Protege
 

My horn died. I checked the horn pad under the steering wheel cover and tilted it up a little bit. Now I can hear the clear "click" sound once I press the steering wheel cover. I am wondering whether this is the horn relay probelm. Of curse, I have not checked the horn itself since I assume the death of horn itself is a rare case.