Honda Civic 2003 Catalytic Converter Replacement


I need to replace my catalytic converter as I just got a new check engine notice. After observing it, I can see it’s in pretty bad condition at the connection points. Especially the flange, it looks pretty deteriorated.

My question is, should I attempt this replacement or have a professional take care of this one? I am a plumber and am mechanically inclined ( I have fixed a few other basic to intermediate car repairs).


I’ve concluded that exhaust work like this is miserable and frustrating for me. And it is amazingly simple and straightforward (and inexpensive) at a good locally owned muffler shop.


I concluded that about 50 years ago when I got tired of dropping rust in my eyes and went to a local shop ang got it done for what the parts would have cost me. This same local shop would always bend what you need and for the last 10 years will do it in stainless.

Rust is a headache at the best of times. Exhausts have rust. This will take penetrating oil and a friction cutting wheel and maybe a bit more to remove the old cat.

You are a plumber so you may be familar with rusty or seized pipes. Give it a go. You can always drive it loud to the local muffler shop if you can’t fix it.

They usually cut the cat flush at one end and weld a new pipe that connects with the old pipe.That repair will last until the car goes to the junkyard.

Here’s another vote for going to the muffler shop.

Sit back and have a cup of their coffee. That’s what I’d do.

Good luck.

Got a car 2 yrs ago with new cats and exhaust. It was beautiful man. Had to sell it though.

As in many other posts make sure the converter is the problem. What is the code?

Removal is easy with the right tools, but I doubt you have a hydraulic lift. That’s the main one. Once you get it up on a lift, it’s easy to saw off the exhaust system, then cut the bolts off where the catalytic converter meets the manifold. You still need to buy the right catalytic converter, one that won’t set off a CEL no matter what. Depending on where you live, a CEL will prevent you from renewing your registration. I’d just take it to a muffler shop. OTOH, maybe you have the tools and time to get the job done right.

Thanks all for all of your feedback!

I put my cat in and I guess as long as you have all the parts you need, ramps, and don’t mind laying on the floor for a while, but who needs it?

I’d never in my life hired a plumber except to plumb my houses that were built but I finally did. We remodeled the kitchen and the new sink drain connections were a bear. One trip to Menards, two trips to Ace and my third stop was to a plumber. He was there the next morning and also had to make two trips back to the shop but done in two hours. The bill was $134. I asked him if he wanted the $60 worth of parts I had bought but he declined. Yeah let a pro do it.

I’ve realized you can either pay in money or pay in time/frustration. It depends on the individual and his/her life factors.

Personally, I’d rather pay a professional 8/10 times. They get it done right the first time and probably better than I can.

And in all honesty…if something goes wrong, my wife can’t immediately blame me. :smile:

Oh yeah? You picked the garage! It’s always our fault, ya know.

Please post the code, there is not a replace the catalytic converter code I am aware of, so you may be wasting your money.