I had check engine light came up again. this time i recorded flashing. it was 05 05. so I went to check the code. it said "No Failure Recorded/Detected"
does this mean there's nothing wrong with the car? or should I still take it to mechanic?
thanks in advance..

 

you may have had the gas cap open or something.. reset it and see if it comes back

 

Is it possible you inadvertantly cleared the ECU while trying to do the readout? I always thought 0505 means "AOK" and doesn't illuminate the CEL.

Assuming the ECU is now reset, you could drive as usual. If there were a problem originally it would still be there and engage the CEL again, giving you a second chance to do the readout. The original problem, if any, probably isn't too pernicious so it's probably safe to drive your car. You would have known if the problem were bad by the aberrant behavior of your car in the first place.

 

It is possible for the Engine Control Module to clear a code if the problem has gone away. If the engine starts readily and operates well, just drive the car normally. If the Check Engine Light returns please do a Diagnostic Trouble Code readout promptly.

 

A loose or missing fuel filler cap sets a Diagnostic Trouble Code pointing to EVAP system leak, such as DTC 0213 or 0705.