Z4-forum.com

Quick facts that may alter your thoughts
*06 Z4M Roadster
*California
*Still new to cars (have many friends who help)

With all that aside I would like some guidance from the community if possible. I plan on throwing on a tuning chip from ESS Tuning, but was told and recommended to get aftermarket headers. I already have a Rouge Engineering X pipe installed. I still have the rear cats. Now I would like to follow through with the headers but still would like to pass smogs and avoid resorting to hot smogs. I was told to get mini cats and it seems pretty straight forward but I have my doubts. I was also told we can delete main cats and move the O2 sensor to the rear cats and keep those. I honestly don’t know how to approach this. Anything helps even links to specific parts, mini cats, headers. Hope you all are doing good and thanks in advance!

Well welcome to the forum - a photo of your pride and joy would go down well on here.

I've only had my M a year (to the day) but from what I have read over my years on here chips and remaps don't give significant power gains on N/A engines, but may alter driveability.

I can't see different exhausts providing noticeable power gains either. My car has after-market back-boxes that sound great but I doubt they add any power.

If it's more power you are looking for supercharging might result in more cost-effective gains.

I appreciate the heads up on the chip tuning. I will keep it in mind and challenge the guys that think otherwise with that. I have considered turbos or a supercharger, but am afraid of killing the lifespan of my baby. But back to the topic! If I was to follow through with the high flow headers, and tune, is there a way to still be able to pass a smog with mini cats as my buddies would call em?

Also I was told I won’t gain much power. At most 40 to the wheel. They had also said if I truly want serious gain go turbo or supercharger. I am considering it for the future but now keep it small gains. I just have zero knowledge in these mini cats or how I can still pass smog after deleting the cats I have. They had also talked about some sort of spoofer for the computer not sure how to approach it. I’m also aware visual definitely will not pass. But the shops here don’t do visual inspections.

I would go thru with none of those things, there's no real power gain from exhaust system, and these "tuning chips" "re-maps" etc, may give you a bit of power but, I don't think the car needs more power to be honest.
good luck with whatever you decide to do!

I think the US headers are much more restrictive than the ROW spec. Maybe switch to those?