I have a 94 Accord and after coming to an abrupt stop at a red light my check engine light came on. Its been on for about 3 years and my car is running fine but it is annoying me. I checked it out and it came out to 9 blinks which indicates a CYP sensor (defective circuit or unplugged or defective sensor). I was wondering how I can differentiate the problem, is there an easy solution to this problem, does this NEED to be fixed, and if I took it to a mechanic about how much will it cost. Thanks.

if its the sensor then just change your sensor, but if in 3 years everything was fine, it doesnt mean it will still be fine, there is a reason a sensor is there, so change it

how can I check it?

the cyp is in the dizzy housing. it cannot be changed. actually it can be, but, it would be cheaper and easier to get a whole new dizzy.

to check it, you need to measure its continuity and voltage. more than likely, the problem lies in the dizzy, not the wiring or ecu. wouldnt hurt to check though.