P0420 cel

[jdmdikk]

I have a p0420 code on my 99 Ek hatch. The code just came on yesterday. I do have a funny misfire when I first turn the car on and then it clears out. My guess is a clogged catalyc convertor due to the code meaning Catalyst system efficiency below threshold (bank1).can I just gut out the stock cat that is on the stock header or would I still have a cel? Would I still have a cel with a aftermarket header? I already passed emissions so I'm good for a while with that but I hate having any cel.

[Rocker]

i gutted mine and the cel still came on :/

[2000GSRtypeR]

Yes you will still have the check engine light if you gut it. That code means that your cat is no longer working up to par.

[Santi]

^^ yea u might need a new or another cat

[hondagsr]

If you already passed emmisons just buy a aftermarket header and just ignore the cel.it will run fine just throw a code for no cat.who cares lol

[Jroc860]

Need a cat homie

[hondaguy]

Buy a header. Use a spark plug defouler

[jdmdikk]

Thanks for all the information.I will look into the spark plug defouler.I might just gut out the cat for now or look for another stock header.