My 2000 Civic with 252k has posted the P0420 code. The converter is the original one so it probably needs to be replaced. I've cleared the code several times and after a couple drives, it comes back on. The OEM one is pretty expensive, so has anyone had any luck with aftermarket ones, and if so what brand. Thanks

 

Same thing just happened to me, only its the 2nd aftermarket cat thats gone bad in 2 years now. I don't have to smog until March so I just had a straight pipe welded on there until then. What Im learning with catalytic converters is you get what you pay for, but you should consider how much longer you think your car will last. The OEM cat will probably cost you about 1/5 of your cars total value, even more if you let the stealership install it.

 

Was doing some research, looks like Magnaflow has good reviews and is reasonably priced. Found a cat on their website for my 99 EX D16y8 that meets California Emission Standards for about $350. Thats about $600 less that stealership.

It is really important that you get the right cat, if you go to the Magnaflow website, enter in your type of car, it will show you a list of all compatible cats.

NOW LOOK ON THE UNDERSIDE OF YOUR HOOD FOR AN EMISSIONS STICKER that has the word CATALYST on it.
LOOK FOR AN EFN/Test Group Name that looks like this: XHNXV01.6TA3

The last 4 digits will vary depending on what test group your car was in when manufactured. Whatever the EFN is under your hood, make sure to buy a cat with that matching number!

 

Great info! Thanks very much for looking into it & passing on the info. I'll do as you suggested & get the EFN/Test Group Name and see what they have. Cheers

 

Well i installed a Megan Racing High Flow Cat on my 97 Civic Hx and its been running good for these past two years not a lot of emissions either also i live in San Antonio, so no smog test are done over here no know but no gas smell comes from the pipe.