integra p0420 code/bad gas milage

[WadeTustian]

well had my misfire codes that im sure some of you remember got all that fixed, then recently i got a check engine light, was a p0420 catalyst threshold below bank 1. im getting extremely bad gas milage for such a small car, like 250km per tank from a 1.8 litre......i know my cars running rich and im getting a new 02 sensor for the front tommorow, hopefully that will help, but will a bad cat cause this bad gas milage? should i try taking it off and cleaning it rather then dropping 300$

[Jayce Carlucci]

p0420 means catalytic converter is clogged. Time for a new one. if you do not change it you will continue to lose power until your car will actually not propel forward

[crispy_chick3n]

p0420 means catalytic converter is clogged. Time for a new one. if you do not change it you will continue to lose power until your car will actually not propel forward

NO NO NO NO!!!!!! a clogged cat wont make your car not move. although it isnt the best thing for them. you can pick up a cheap aftermarket cat for like 60-80 bucks, and with some welding skills you can cut the old one out and put the new one in in about an hour, or if you dont have a welder, you can always clamp it on. it needs replaced. there is no real good way to clean it out without destroying it.

[Cboeger]

You need a new one, I have to get a new one for my Ford Focus next week, trust me it's worth it in the end, you won't lose power while trying to accelerate, especially going uphill and also you'll get better MPG and getting a new o2 sensor is oreillys/autozone talk, you need a new cat, although it would be beneficial to replace your o2 sensors while replacing your cat.

[Nico Shull]

Please do the right thing and replace the components that need replacing. I have never seen anything good from "cleaning" a catalytic converter, or O2 sensors for that matter. Always better to err on the side of caution and go with new components!

[crispy_chick3n]

Please do the right thing and replace the components that need replacing. I have never seen anything good from "cleaning" a catalytic converter, or O2 sensors for that matter. Always better to err on the side of caution and go with new components!

ive seen someone who cleaned out their cat with some kind of chemical (cant remember the name) and it left a nice residue, and it actually caught fire from the heat. lets just say that car is no longer in existence. you can clean o2 sensors and they will be fine, but they may not perform like they should, throwing codes once again. O.P. just pony up the dough and replace them, its worth it in the long run.

[white4d96]

If you don't have to pass emissions, you may be able to run a test pipe in place of the cat. You would, however, need to run a rear o2 fix (either an emulator, or a restrictor; I used a sparkplug non-fouler for mine) to cheat the car into thinking a functional cat is in place.