I need to replace the exhaust manifold / catalytic converter on my 99 Civic LX.

I am looking at an aftermarket replacement part.

For some reason, the studs linking the cat to the exhaust pipe are welded to the flange.

What are the benefits of welding the stud to the flange? It seems like it would be easier and cheaper for the manufacturer to just have holes there, so what's the point?

What if the threads on these welded studs ever get damaged? Or the stud itself breaks?

Thank you.

 

I bet they are just tack welded to the flange. Probably be able to just tap them out with a hammer. My guess is that incompetent idiots install these and claim they keep coming loose or something. Or maybe it makes the assembly process easier for them?

 

Just seems like a strange choice given that the OEM part uses regular studs.

 

Probably better not to over think things. lol

 

I specialize in over-thinking...

Just wondered what would happen if one of these needed to be replaced, but I agree with you that they might just pop out if tapped with a hammer.

 

for this part especially, studs allow easy assembly from beneath without needing to hold a bolt on top from spinning. it's better than threading these holes and installing bolts from the bottom because they maintain alignment of the flanges durring assembly.

i've seen other OE applications where the studs are press fitted instead of welding. better still because it's a more repeatable, reliable method. however not always best for lower volume (per run) aftermarket parts like the one pictured.

unless you live in the rust belt, these threaded fasteners will long outlast the catalyst. that is assuming they've been installed to spec and the rest of the exhaust is fitted properly (not hanging loose without all brackets in place.) but if they do rust beyond recognition, like you said blunt force removal shouldn't be an issue.

 

Interesting, that makes sense.

 

ease of install.

 

Ease of install and less chances of striping threads when you install.. Aftermarket places are just trying to replace OEM so they do the same.

 

Yes, but the OEM has threaded holes on the flange and uses studs that are not welded.

So I was trying to figure out why the manufacturer would chose to use welded bolts rather than threads and studs.

I suppose that threading the holes could be more expensive.

 

Nissan also have welded studs, well I'm not sure on each model but R34 Skyline, M35 Stagea and S15s they are