2000 Boxster S exhaust manifolds
 

My 2000 Boxster S 6-speed has at least one crack in the exhaust manifolds. With the car on a hoist, I can see a crack in the header pipe just inside the flange where it bolts to the head at cylinder #6. The symptom is a tick sound (like a cracked header) which is very noticeable on cold start, but becomes less audible as the engine warms up. I have identified three inexpensive repair options:

1. remove exhaust manifold/cat assemblies and repair the cracked areas by welding, then reinstall

2. buy cheap headers on ebay, then install and relocate the downstream O2 sensors after the main catalysts, preventing the car from failing the cat efficiency monitor

3. buy used 1997-99 2.5L stock exhaust manifolds and cat/pipe assemblies. Relocate the downstream O2 sensors to the 1997-99 post-cat locations. This approach has the advantage of appearing stock to a California smog inspector, as long as the individual does not know their Boxsters really well. Will the 2.5L manifolds match the 3.2L ports? I don't know.

I am new to Boxsters, but I have been ASE Master and L1 Advanced Engine Performance certifed since 1998, so I don't anticipate any major problems doing the work myself.

Which option has the best chance for success?

The cheapest is to remove the manifold and weld it. If you find out it's "wasted", then I would go with the E-bay headers. Hopefully this car isn't the DD and you can afford some down time.

Good luck

I've got a set of stock/oem 986 boxster S exhaust manifolds, along with a set of aftermarket boxster headers available... PM me if you're interested in either of these.

FWIW, Option 2 does work albeit barely. I passed 2 smog tests with that set up. The second time failed a few times first, but it was for other reasons (bad o2 sensor and MAF). Worst case, you can temporarily reinstall the OE headers if you fail.

Headers
 

I have a 2000S and put on the headers. Make the change, you won't be sorry.
Rich