I am going to start adding up the items needed for a California Smog passable Ebay headers setup.

[Dean]

I have been interested in Ebay headers for a while, and have done a good amount of research. I want to tackle this along with some other cosmetic projects over summer.
I live in California so Smog is an issue, and I want to be able to pass the sniff test. Visual honestly has never really been an issue, and once I paint them with a black ceramic paint, they should look mostly OEM.

My plan starting from headers back is-

New hardware
Headers
Straight pipes (dual)
02 sensor (pre cat)
Remove OEM resonator #1
X pipe to dual high flow Offset cats.
O2 sensor (post cat)
weld OEM exhaust rear end to new front end
OEM resonator #2
OEM ZHP muffler


Should be what I want...Im hoping all goes smooth when I take it on.

Im looking at 100 for headers, 200-250 for cats, 150 for welding, 100 for additional components. Total is about 600.....

Feel free to throw your likes or dislikes. Il create a write up when I take it on with prices and pictures if desired for us ZHP folk.

[Go Horns!]

I'm interested in seeing how this goes. I want headers, but I want to be able to pass a sniff test.

[johnrando]

Dean, I'd love to see how this works out, as I'd be interested in the same set up. BTW, where were you thinking of getting the work done?

[Dean]

Alright Update:

I got some quotes today, looks like about $425 to get catalytic converters welded in line with OEM exhaust (with bungs for O2 sensors) in place of the front muffler (resonator). I plan to leave the bolt on area in tact, and request a new elbow with extended piping going in to the new cats, and the have the OUT of the cats be welded into existing OEM rear exhaust.


http://www.realoem.com/bmw/diagrams/c/y/121.png


The entrance for the resonator is currently about 45 degrees, I want to add another elbow to create a 90 (as I described) so the cats can be a straight in-out. I have extra pipe room to work with as you can see.


Here is the Cat I will most likely be choosing: 17 inch in length with a 7 inch width.

http://static.summitracing.com/global/images/prod/large/MPE-38008.jpg


http://www.summitracing.com/parts/MPE-38008/

Elbows like so:

http://static.summitracing.com/global/images/prod/large/imm-50019_w.jpg



I am going to figure out pipe diameters and measurements shortly. Anyone else have good measurements, feel free to let me know.

[Dean]

Dean, I'd love to see how this works out, as I'd be interested in the same set up. BTW, where were you thinking of getting the work done?

Still picking a place, have not committed to one. I might just do the measurements and order/bend/weld the pipe with a local friend who has the tools.

[Dean]

Update! measurements.


24 inches from beginning of existing resonator to next exhaust bracket. New catalytic converter is 17 inches. leaving 3.5 inches on each side to play with. Definitely a close fit, but it will fit without modification.

[LivesNearCostco]

Am curious, did Dean ever finish this project? If yes, how do you route the post-cat O2 sensor wires? Do you have to extend them?