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My 99 Civic Lx (112k) has a cracked exhaust manifold. I know this is common on these cars, and that the exhaust manifold is welded to the cat. I was just wondering on replacement recommendations. Everything under the hood is stock, and I'd like to keep it that way. I' was looking at the 2 piece Dorman, and the Walker manifold/cat combos from NAPA. Or for just a little bit more I can get an OEM manifold from Majestic Honda...but it won't have any warranty. I just don't wan't to have to replace the part again in a few years because the cat has failed, or the manifold has cracked again....Any recommendations?

FYI: I don't live in CA, and the crack isn't bad enough to throw a CEL yet.

 
Rep Power: 518

Do some searching here..... People have talked about brazing the cracks shut, maybe you can make yours last a while. Depends on how bad it is though.

 
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Used ones seem to sell on ebay for 50$ or less shipped. Just did a quick search. Don't know about the long term reliability. Let us know what you do.

 
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So after a few days of research and reading reviews this is what I found:

It seems like no matter what brand, no aftermarket converter is going to last as long as an OEM. The problem is that OEM converters cost more, have a shorter warranty, and the exhaust manifold cracks.

I was also told by NAPA, and my local mechanic that even though I don't live in Cali. the car needs a C.A.R.B. converter because it has Cali. emissions since the car was originally sold in Cali. or it will trip the CEL.

So think I'll end up getting the Dorman 673-439 from O'reilly's since it has a lifetime warranty, and a purchase that big will get me a $5 coupon with my rewards card.

 
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Never heard about the Carb converter or throwing a CEL of it. A cracked manifold is always bad I had one on my 97 sedan and it cracked all the way around. Had to have it cool down before I replaced it. I would think the cel would come from the Ecu but I have never seen any extra wires on the cat. Unless it uses the O2 data.
If anyone knows here knows it would be Ezone.

 
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CARB stands for California Air Research Board.

They have their own rules and regulations that are more stringent than the Federal emissions guidelines, and they dictate longer warranty terms on many items. THAT is why I recommend them, it has nothing to do with the emissions specs of the car itself.

When I put my name on a work order, I want to assure myself and the customer of the best fix. I do not solve problems by letting some hack weld in the cheapest cat they can get their hands on, but sometimes that's all we can do for some people. If it is bad, it's bad. I recommend my choices, then they are free to accept, or decline repairs and go elsewhere.

A CARB Certified cat is supposed to be far better than a cat that is allowed to be sold in the rest of the country.
You cannot legally buy a non CARB certified cat for an OBD2 car in California.


Factory has the best quality cat (the cat guts, not necessarily the manifold section of it), regardless of the 1 year parts warranty.
Cali certified cat has a 5 year warranty. (Someone research this, don't believe me),
The rest of them have 1 year if you are lucky. Many don't even last that long.

This is an instance where you really get what you pay for. Precious metals and all that.

NOTE: A poorly running engine can ruin any cat in only minutes! It does not matter if new, old, cheap or expensive.

So: Factory cat is first choice
Calif CARB certified cat is second choice
(The last choice shouldn't even be offered most of the time.)


A cat itself has no wires.
The PCM can only use the O2 sensors to monitor the condition of the cat (measuring its capacity and ability to store and release Oxygen).

 
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ezone, just to make sure I understand...

just because the car was manufactured with a CARB converter doesn't mean the cars computer will throw an error code if I install a non-CARB converter.

That being said, I shouldn't even consider putting in a non-CARB converter because it will almost certainly fail in a few: months/thousand miles.

Assuming I understood you correctly, do you have any recommendations/warnings on converter brands?

The model I'm considering is the Dorman 673-439, it is CARB certified and has a lifetime warranty. I figured it's pretty hard to go bad with a lifetime warranty.

I was also planning on replacing the upstream O2 sensor. I've read that a cracked exhaust manifold can kill them. I pulled it out to look at it the other day and it's covered in white dust/residue. Thoughts?

Thanks.

 
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In this case, CARB regulates the replacement parts, not the original parts.

The car was manufactured by the factory equipped with a catalytic converter that meets Californias emissions regulations, not a converter sourced from or approved by CARB.

(For all I know, the Original Equipent cat on a California car was the same as the cat on a non-California car.)

A company selling a cat that is not CARB compliant will not even ship it into California.
True.
The questions are,
1) "How long will it last before it fails?" and
2) Does it have to pass an emissions inspection? If so, what are the rules in that area?


Not always, but it can and does happen that way. The choice and risk is yours.

Can you afford the labor to replace each failure?

As a professional, I hate to even mention the cheapest cat choice because the failure rate is simply too high. When I FIX a car, I want it to STAY fixed.

IMO, You can go on down the street if you want a cheapo. Be mad at those guys when the cheapo fails way too soon.

Google
CARB compliant cat

I have no opinion here.

Most anything sold by Autozone comes with a lifetime warranty too, but do you think I rely on their parts for MY customers?

The warranty is no indication of quality.
The warranty is all about marketing.


Visual observation is not a relevant factor. You cannot evaluate performance that way.

If you replace it, replace it with the exact same brand the factory installed in it. Same part numbers and all.

 
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Hmm... alright thanks for the info. Looks like I'll be getting a CARB certified converter, but It'll be at least a few weeks before I have the time to get to it. I guess I have some more researching ahead of me to decide on a brand...

Thanks again.

 
Rep Power: 518

Converters designated “California OBDII” are designed to meet the more stringent requirements as set forth by the California Air Resources Board. Converters bearing this designation perform better and are covered by warranty for a greater period of time than standard aftermarket replacement converters.

https://www.magnaflow.com/02catalyti...ics/04carb.asp



Once you step into the area of a cat that is certified to be compliant with CARB regulations, you should be more assured it meets a minimum standard of quality....brand names become less relevant IMO.



I was poking around on the Majestic site....I didn't find an option for California Emissions on a LX.......

The only car I saw available with California specific emissions was HX coupe.
My dealer parts catalog seems to agree with that.
The converter itself is no different, same part numbers for Cal and Fed vehicles.

 
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Regardless of how the manifold is fixed and/or replaced, I always cringe at removing decades old exhaust manifold bolts/nuts/studs. Thousands upon thousands of heating and cooling cycles along with moisture usually do their number on them and invariably one gets snapped off inside the head. Good luck getting them off, but be prepared if/when it does happen.

 
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Hey man, I have a Dorman, same model number 673-439. I have had it for a while now like 2 years and no issues. It was a little bit louder, but overall it performs the same in my book. No CEL, that is until my 2nd o2 sensor died. I still need to replace that ...

 
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Oh and a note on this. Get some PB Blaster and spray it on the exhaust bolts on the engine, connector flanges, anything yu will need to remove. Do it nightly for like a week before trying to remove it. This worked wonders for me, every bolt came off fine.