What does it mean when the check engine light flashes while driving the car?

 

Usually that is indicative of multiple misfires...

Sounds like time to scan for codes and see what's pops up.

Did the car get a new cam or other mods?

 

^ Yep. Flashing SES can only mean one thing: serious misfire. You will likely see a DTC P0300 and a P030x (x = 1-8, # will correspond to the misfiring cylinder(s).

 

So it looks like I have a misfire on #4. Not sure what is causing that. My OBD codes are P0304 P0161 P0332. Was running just fine, now this. Any thoughts?

 

Yeah, you need to diagnose your #4 cylinder misfire.

 

I'd start with the simple stuff by swapping coils, injectors, plugs and wires from the #4 w/miss to a known good cylinder, one at a time.

Process of elimination. If the misfire moves to the good cylinder you'll know the swapped part from #4 is the likely culprit.

Also inspection of #4 plug may give some clues depending on how it looks.

Chasing a misfire one time, discovered the cause was the spark plug insulator was cracked. Replaced plug and end of misfire issue. So now I like to check misfiring cylinder's spark plug early in the process.