Cracked manifold/clogged cat

[cackalak]

Found the cracked manifold after the CEL tripped. Which means new manifold/cat (or catifold, as it's been called). Are you guys using OEM? (those that have had theirs crack). Or aftermarket? Autozone has one from Bosal that's ~$350. OEM is $450. But the Bosal has a lifetime warranty. Not sure which to go with.

This is what I saw after I removed the heat shield.



FYI, there is a Honda extended emissions warranty which covers all of this. 14 year/150,000 mile. Mine is about 20k over that, so out of luck.

[nervousmini]

Bummer - sorry to see that, but it seems a pretty common failure point.

I would go for the Bosal. Usually I'm all for the OEM piece as they are typically better than aftermarket, but the OEM has an obvious design flaw. Besides, if you have ever really looked at Bosal products you can really see the quality in the parts they make. I use their stuff to fabricate race exhausts all the time.

Don't bother trying to have the crack welded up for a repair - it won't hold, I've seen it tried too many times to entertain wasting another second on it. The repair weld typically lasts about 2-3 months then cracks again.

[cackalak]

Thanks for the feedback. Do you think the Cat is bad? Or is the CEL from the cracked manifold. It's throwing a P0420 code. If the Cat isn't bad, then I might keep it around to use later, if needs be.

[drimportracing]

I'm GUESSING that the catalytic converter is still good. With the cracked manifold you were escaping gasses and sucking air that the second O2 sensor picked up, this is probably what threw the CEL code.

To blow up a cat:
If your car had an aftermarket 2 stage rev limiter designed to limit rpms by ignition control then you could easily reach a preset limit that would still allow gas to pump that would not be ignited as the rev limiter disables the ignition, and if held for two long...6-10 seconds then you would fill the cat with unburned fuel until it eventually ignited and explodes the internals of the cat causing it to block the exhaust path which increases back pressure until valves are bent.

You probably don't have such a problem.

If a cat were blocked it is illegal to take a 2 foot long metal rod to the cat and knock out the remaining internals. Just thought you should know. - Dale

[cackalak]

Ha ha. Thanks, Dale.

I also found another "catifold" from Checker's Auto.

http://shop.oreillyauto.com/productd...pe=145&PTSet=A

It's $100 less at $250, and still has lifetime warranty. I think I'm going to pick this up.

EDIT: Found just the exhaust manifold online. $53. My car just passed emissions a week and a half ago, so I'm guessing the cat is still good.

http://www.car-stuff.com/carparts/ho...bh9607011.html

[PaleMelanesian]

Nothing to add except that mine is starting to crack, in exactly the same place. I'll be listening to how you handle yours.

[Shan]

try ebay for a cheap aftermarket header. I bet they can be had for $100 or less. I know I have bought a nice one off there before.:

here is the one I bought (on the left for $100 from ebay):




oh, how I miss that car.

[cackalak]

Thanks, Shan. However, in the HX (and all other models except the EX), the manifold is built onto the cat. Someone did suggest using an aftermarket header for an EX and relocating the cat under the car. However, I will need to extend the O2 wires and it could cause a CEL because of that.

This "catifold" design is a flawed design from Honda and numerous 96-00 Civics, as well as 01-05 Civics have this problem. They did issue an extended warranty, but only up to 150k miles for 96-00 and IIRC, 80k miles for 01-05. IMO, they should just do a recall and take care of them all, regardless of mileage, if they start to crack. Just like Toyota is doing with Tacoma frames.

PaleMelanesian - I just ordered the Dorman from Checker's. They price matched with Autozone, which was $230. Comes with all the gaskets and such. I found out that the OEM manifold is WELDED onto the cat, which means if one fails, you're replacing the whole thing. Brilliant. So the $53 manifold idea is out the window. But at least this manifold and cat come with a lifetime warranty. I'll post up the aftermath. I should get the unit tomorrow and will install at night. I just hope I can get the O2 sensors off without problems or I'll have to buy new ones.

[PaleMelanesian]

I've looked in a few scrapyards, and every one i found had some sort of crack as well. I agree - flawed design.

[aaronl]

My '00 has the same crack in the manifold. It's very common. I believe I had a window of a few years to get it fixed under an extended emissions warranty, but for 2000 models it's only 7 years or so, and it expired before I found out about it.

It's a particularly expensive problem in California because the OEM manifold/converter is basically the only choice. I've seen a few slightly cheaper models on eBay that claim to meet California emissions standards, but I wouldn't buy one of them unless I had a guarantee that they came with the necessary CARB documentation.

In my case, it doesn't affect the engine negatively or introduce measurable levels of carbon monoxide into the cabin. It mainly hurts the resale value, which must be near zero already because of the salvage title and the peeling paint. It wouldn't be a big deal if I was going to drive the car into the ground, but I'm planning on replacing it with a manual 7th gen Civic soon, so the crack is pretty unfortunate.