i'm new to this site,it's great .first off i would like to say hi to everyone .next i was hoping that you guys could help me out . i have a 99 cl 2.3 . i had a cat failure the inside broke ,so i took it off and removed every thing inside .so basicly itis like a big straight pipe there is nothing else resticting the exhaust except the high flow muffler i installed.also i live where there is no emission testing .my problem is that i am getting a p0420 code i looked up the code on this site and it is catalyst system below threshold bank #1. i do not want to replace the cat if i dont have to i would like to keep the exhaust restriction free.i found a site o2 simulator do you all think these will work .i also installed a short air intake .any info you all could give would be great .thank you in advance.

 

your getting the code because there no catalyst left, second o2 sensor read cats effiency. keeping it hollow won't gain shit but useing more gas and clogging up your egr faster.
i had to replace mine, i got a new 98 2dr accord cat off ebay, worked great, passed emmissions and fit/bolted right in stock location

 

yea, no matter what you do to the car, its still gonna be slow with that engine. I had the same situation, only mine appeared naturally. What did i do?

http://forums.evolutionm.net/evo-how...ouler-how.html

Illegal? yes
Was it noticed during inspection? no
Did i pass? yes

Even before that, i replaced both O2 sensors, fixed exhaust leaks, and did a tune up to try to get rid of the code. Nothing worked, but i didnt want to spend dolla dollas on a new cat, so that mod worked just fine and i still get 30mpg.

 

 

word. definitely the easiest and cheapest fix. And if you don't want to try to drill through the antifoulers you can buy a part on ebay that's already machined to the correct length.
oh and don't forget antiseize on the threads if you plan on taking it off in the future.

 

Anyone with the P0420 ever bought it back to the dealer for a 8year 80k warranty on the Cat replacement?