I just fill my car up at the gas station, when I started it and heard a pop noise. The check engine light started flashing, the car was making a loud noise and a little bit of smoke came out the back. The only code I got was P0420. I have checked the plugs and coils( there a couple weeks old) they looked good, Theres no oil on them. My O2 sensors are a few months old.

Does this sound like I need a new catalytic converter?

 

I got a set of weird codes at the gas station. Try this just for S***s and giggles. It worked for me and it's worth a shot.

It's complicated so listen up...
Undo the gas cap
Let the tank "breathe" for 5 seconds"
Tighten the cap to 3 clicks
delete the code and see if it comes back or not

I know... it's complicated

 

p0420 is a cat. code 9 times out of 10 its the cat and aftermarket cats suck. if you had a miss or a front o2 that was bad for a time you may have burned up the cat over time. it only takes a 15-20% clog to set the light on a obd2 car (96-now). if you use a aftermarket cat reprogram the pcm with any new updates that are out even new car have pcm updates.