Cameltoe

Hey Gents,

I got a 2000 Civic EX with the 1.6L SOHC, and I threw a P0420 code (low cat efficiency). The car for the most part runs normally.

On my search, this was the only thread I found on this: http://www.torontocivics.com/tccv5fo...ighlight=P0420

I learned back in July that the car has a small exhaust manifold leak due to a crack, so it might make sense that constantly running rich might strain the cat. It has probably been there for a few years, but it passed the DriveClean with flying colours 2 times over the past 3.5 years.

Car has NEVER given off a rotton egg smell.

So I wanted your experienced advice....I don't think I'll keep the car long-term. Should I fix the cracked manifold (i.e. target the source), or just replace the cat with an aftermarket unit to temporarily alleviate the problem?

If vacuum leaks can be a possibility, is there a particular area or set of hoses I should mind? Hope to get your advice. Thanks very much.

CivicOnBlades

Id say replace the manifold if you know theres a leak coming from it.
But im not sure that a leak at the manifold would through that code? I could be wrong.
I wouldnt just automatically replace the cat....cause there not the cheapest and sometimes aftermarket cats can through up a code as well.
Thats just my 2 cents.

chris_v2

Replace the cat and manifold assembly. The cats prob. toast from your exhaust leak.

Cameltoe

Just a follow-up to my original post from almost a year ago on my 2000 Civic with 250K. I got the P0420 last fall and replaced the cat/manifold combo with an aftermarket unit. It's been fine, but the P0420 came back today, along with P0300, P0301, P0302 and P0303.

In your experience, do you guys think the manifold's cracked again, or do I probably just need a tune-up? I did the plugs back in March, but cap and rotors and wires have not been done for 80K.

I did a search for other options, but nothing seemed to have come up other than code discussions. Hope to get some feedback on how to proceed. Thanks.