I have a 2004 Dodge Neon Srt-4

I have a 2004 dodge neon srt-4. Its a 2.4L turbo. I have getting a trouble code that reads P0301 and I know that is a cylinder 1 misfire. I hear a popping noise coming from my exhaust at idle and the crackle from the exhast that I normal have is no longer there. I recently changed the spark plugs and wires. However, I am still hearing the noise and getting the same code. What could this be/what could I do to fix this? Also the check engine light only flashes every so often and stays on at random points or remains off for days. Any advice or suggestions will be greatly appreciated.

if it makes any difference the car has a catless downpipe and a dual exit exhaust with no resonaters as well as a few other modifications.

thanks