Is it possible to pull up check engine codes without going to a mechanic?

My check engine light comes on once engines is started, engines doesn't fire properly when slowing down, seems like on cylinder doesn't fire. Took spark out (they where white) and made sure gap was OK. Fired it up and everything was back to normal. After about 10 miles it started again, engine ran but no power. Could this be the ignition coil?

Thanks

 

Yes. Here you go. Might need to be specific as far as year though. https://www.hdforums.com/forum/elect...tic-codes.html

How many miles. Could be anything from a fuel filter to a pin hole in the fuel line Welcome to the forum.

 

Thanks.