legendarysouls

I going to buy headers and need cats. Budget is 6-700.

Best deal I can find is bbk headers 370 shipped

And then have cats welded in. Which cats will work? I know the y pipe is 2.5 in.

Do I need o2 extensions ? I am also removing the egr emissions system to fit my ls6 intake. So I would have to buy the 01-02 bbk headers?

I am also going to buy a PCM from sponsor/vendor here what codes do I have them remove?

99z28 a4 with magnaflow cat back
Thank you
I would like order everything this week end

Tranz Zam

Get whatever cats that have a 2 1/2" inlet/outlet, and will fit within the shape of the y-pipe. You can get some cheap ones off of Summit or Jegs.

Yes, you should need o2 extensions. I think they'll need to be around 16" or so? Others will chime in on the length of the extensions. The rear o2's should reach.

Buy the 01-02 headers if you plan on removing the EGR. That's one less thing to leak on the headers.

Remove any emission codes. Since you're keeping the rear o2 sensors, leave these working. Have them remove the EGR codes, and the AIR pump codes. Unless you're keeping the pump in place, then you can leave it alone.

RevGTO

iTrader: (12)

^^^. I would personally use a round metallic core cat - Magnaflow (more expensive, proven quality) or Thunderbolt (cheaper, good reputation).

Frost is a well-known tuner on here. Tell him what you've told us above and he'll get your tune set up properly for you.

Tranz Zam

A Frost tune would be a nice thing to add to the list. With it, you can take full advantage of the mods you're doing, but if you don't want to spend to much find a local shop or buddy who has HP tuners and have them go in and shut off the egr and air codes. Most places charge around $125-150 for just that. Its $100 for the two credits, and whatever they feel like charging for their time.

Blownbayou

iTrader: (7)

I pipe with the BBKs will not reach the mid pipe also..... Most are a hair short. I had to use a clamp to get them mated up. Then to the welder I went. Other than that.... Great header for the price.

mjs1012

iTrader: (36)

With my BBKs and ypipe I needed a 3" id/od adapter to add to the end of the I pipe since both the y pipe and I pipe are the same diameter.

73CamaroLT

iTrader: (8)

Yep same with me^ but mine fit finally. Was actually alittle long with my LM2 catback and messed up the alignment of it lol.