choices for replacing catalytic converter

[derolph]

I'm planning to replace my catalytic converter (cc). My car has 180K miles on it and still has the original cc. I want to do this because I believe the cc might be having a negative impact on performance.

I see two options on the market. One is a universal cc; these are the lowest cost; they do not have flanges on the end and, therefore, would require some fabricating to get connected to the other sections of the exhaust system. The other option is a cc with flanges on both ends; they would be easier to install since the components in front and back of the cc have flanges on the ends. I will have a repair shop do this.

The price difference for MagnaFlow, for example, is $58. The specific products to derive that cost figure are MagnaFlow Universal Catalytic Converter 53004: Purchase the best Catalytic Converter at Advance Auto Parts and MagnaFlow Direct Fit Catalytic Converter, Stainless Steel 22623: Buy best Catalytic Converter at Advance Auto Parts. The actual parts cost difference would probably be less because clamps and perhaps other parts might be needed for the first option.

Interested in opinions on this issue.

[HLW]

A couple of months ago I installed the CARB legal direct fit Magnaflo cat on myself (I'm in CA). It is not hard to change but you will need to get 6 10mm bolts, nuts and possibly washers (I used the washers becaues the holes on the flamges on the cat are for 12mm bolts).

The back of the Magnaflo catdoes not have the grove for the factory gasket. You can use an appropriatly sized header flange gasket for that but when I did mine, I realized that too late and installed it without a gasket and haven't heard an exhaust leak from it.

If you have a jack and jack stands, I'd recommend getting the sieect fit cat and installing it yourself. I did the whole thing in a couple of hours. It may take a little longer if you have a hard time with the rusted nuts connecting the cat to the rest of the exhaust.

[MessyHonda]

If your state does not require Smog or emission test I would just Straight pipe it. I gained 15whp buy installing a header and a Test pipe. car is dyno tuned.

[derolph]

If your state does not require Smog or emission test I would just Straight pipe it. I gained 15whp buy installing a header and a Test pipe. car is dyno tuned.

Ohio does not have an active emission testing program but they do have the Ohio’s Vehicle Anti-Tampering Law, which makes removal of a catalytic converter illegal. I found info about it on the Ohio EPA website. So, I don't think replacing the catalytic converter with a straight pipe is an option here.

[derolph]

What about the OEM heat shield that bolts on, on the bottom side of the cc? I haven't had mine on for awhile. It's in bad condition due to rust. I imagine a missing cc heat shield is common on old vehicles.

I believe the main purpose of these shields in to prevent the cc from touching some combustible material/matter, such as dry vegetation during a drought, and starting a fire? By using common sense about choosing where to park and drive when off of paved roads, I see practically no chance that's going to happen here in Ohio.

[carotman]

I wouldn't worry about the CC "rattle plate" (that's what we call the heat shields here). Almost every cars older than 4 years old has that plate removed here due to a rattling rusted bolt holes.

The CC can get quite hot in the summer and that plate is indeed a protection for where you park. How often do you park on grass?

[88Sleeper]

If I can chime in, I've looked at this myself, since I was consider replacing mine when I had to redo my entire exhaust south of the manifold...(the flex breaks [at the top]and leaks exhaust, if you're looking for a leak =\ )

I'd recommend the magnaflow Hi-Flow CC if you need a new one. If your ceramic core isn't broken, I'd just leave the one you have (they clean themselves out from heat of combustion, so they're self-maintaining in general)

My heat shield is rusting, but I didn't know they fall off (thx for heads up!)

Oh, and if you've got a weird "rice" rattle when you rev your car around ~3k rpm, it's because the little metal plate that screws onto the bottom of the exhaust manifold is missing the 2 screws that hold it to the manifold. I replaced mine with OEM screws, and it took care of that about 3 years ago, and they apparently fell out somewhere, since mine are gone again and I'm ricing around again =P

If you're not passing the smog check, keep your old down-pipe & flex & cut the end of the flex closest to the rear of the car, about 2/3 around on the top, and go do the smog check again, I've been getting remarkable results at the meter that way =D
That, and having a 2.25" straight through can prevents the sniffer from getting a direct whiff.

For the record, I deleted my egr since it hasn't worked for forever (I deleted it looking for exhaust leak, learned later that the valve itself gets clogged)

[derolph]

I rarely park on grass, and, when I do, its usually a lawn that has been mowed. So, the grass isn't going to touch against my CC on my Accord with regular suspension. Also, the grass is usually green, so it would not be prone to catching on fire. I would be extra cautious if I were parking on dry/dead grass or weeds.

I wouldn't worry about the CC "rattle plate" (that's what we call the heat shields here). Almost every cars older than 4 years old has that plate removed here due to a rattling rusted bolt holes.

My CC shield is badly rusted was causing some rattle when it was on. So, yeah, I'd rather leave it off.

I'd recommend the magnaflow Hi-Flow CC if you need a new one. If your ceramic core isn't broken, I'd just leave the one you have (they clean themselves out from heat of combustion, so they're self-maintaining in general)

Honestly, I'm not sure whether I need a new CC. The decision to replace it was somewhat exploratory; I'll know after its replaced whether it makes any difference in how the car runs.

If you're not passing the smog check, keep your old down-pipe & flex & cut the end of the flex closest to the rear of the car, about 2/3 around on the top, and go do the smog check again, I've been getting remarkable results at the meter that way =D

Ohio has a non-tampering law which prohibits removal of a CC, but they do not conduct smog tests except in certain areas, such as in and around Cleveland.

For the record, I deleted my egr since it hasn't worked for forever (I deleted it looking for exhaust leak, learned later that the valve itself gets clogged)

You mean you removed the EGR valve?

[88Sleeper]

I pulled the pipes coming from the exhaust manifold to the valve, and welded some stainless steel bolts into them, then cut them off and smoothed out the remainder, so they're closed off. You don't want to pull the valve because it has vac lines going to it.

I have no idea if my valve works out not, but I don't particularly care either.

Egr only recycled between 5-15% of the exhaust on our cars, so it's not so bad to remove it, compared to, for example, a brand new accord.

Supposedly, your car will run hotter due to egr providing some internal cooling by lowering combustion temps, but I've not seen that whatsoever.

[derolph]

Thought I'd mention a CC (catalytic converter) recycling option for any of you who replace a CC. I discovered a recycler for my old CC and shipped it to them and received $82 from them. By obtaining the shipping label on the USPS website, the cost of shipping was about $9 from my home in Ohio to the recycler's address in New Jersey. You can get some pricing information on their website @ Catalytic Converter Recycling- Rockaway Recycling I suggest you contact them by email before shipping a CC to them. When I contacted them, they asked me to send photos of my old CC. I sent to photos via email and they quoted a price for my CC.

[gp02a0083]

Thought I'd mention a CC (catalytic converter) recycling option for any of you who replace a CC. I discovered a recycler for my old CC and shipped it to them and received $82 from them. By obtaining the shipping label on the USPS website, the cost of shipping was about $9 from my home in Ohio to the recycler's address in New Jersey. You can get some pricing information on their website @ Catalytic Converter Recycling- Rockaway Recycling I suggest you contact them by email before shipping a CC to them. When I contacted them, they asked me to send photos of my old CC. I sent to photos via email and they quoted a price for my CC.

we are big on the converter recycling around here, so much that people were cutting the cats outta the cars and trucks in parking lots. last IIRC the truck converts go for around 80 and the car ones were like 40 or 50 per cat. Funny you mention rockaway recycling, that is the place I go to e-scrap!