Civic Driving Problems (Limp Mode)

I’m not sure where this would go on the forum, but my car runs like crap. I just got this 00’ civic with 170k and ran great for the last month until the last 3 days. It wont rev over 3.5k rpm and seems like its in a limp mode. It will not activate vtec and the check engine light is intermitent. The code comes up as - P0420 Catalyst system efficiency below threshold (Bank 1). I am not familiar with hondas and would like any insight anyone may have on a repair.

My thought from searching is a clogged or bad converter? Any opinions is appreciated.Thanks.

check your oil

I’m not sure, but I would check the O2s and the converter out for a start.

All good suggestions so far…

UPDATE: Oil level and pressure is normal, o2 is good.

Cat doesn’t sound like any material is loose or broken inside, but the car did stall today while driving. It started up but ran rough with no exhaust tone and then died again. It restarted i gave it a rev and took off like normal.???

Sounds like what you described is the muffler bearing.

^^lol. nice .:biglaugh:

↑ Its probably the cat like you said, my old tracker did the same thing the honeycomb came loose inside and it was clogging it. Take it off and give it a look. I would go to o2 sensors if if checks out.

Thanks man ill take it apart in the morning and give it a check. Time to go cat-less

I would. Dont forget the car does have 170k on it.

how do you know pressure was normal?

My brothers civic acted like this.

The honeycomb in the cat melted into a ball and was clogging under load. Drop the cat.

I’d check your MAP sensor.

Problem Fixed !!! Thank god, drives great now. pulled a ton of material from the cat, was clogged shut.

congrats on fixing it. that picture is super small and doesn’t get bigger, what is it?

i took it on my phone ill get a better one later, its the honeycomb melted and in chunks. Theres also a fibrous band of some sort that was in there and just allot of broken material.

Save the precious metal. lol. Good job.

Good stuff :tup: