Hey guys, thanks again for the advice on installing headers, it went pretty smoothly!

Now I'm onto tuning for the extra flow and one thing that jumped out at me was I can now target around 35-36 degrees in the 5000+ rpm range without knock retard, where before the headers I could really only get 32 on a good day.
That made a huge difference in power! Is that normal for headers to help timing advance or was my cat just plugged right up?

In part throttle cruising the headers only leaned the tune up about 5BLMs give or take 2, which I though was a little lower than expected but I richened it up and it's back to perfect now.

I am going to be ordering a wideband o2 sensor soon and I was wondering if I should lean it out more with headers @ WOT or richin it? Currently it's targeting 12.7:1 I left some room for error because I don't have a wideband yet.
I won't be on a dyno for another month probably but when I do get the wide band next week should I lean it up to 13.7ish or is that to lean?

Thanks!

 

Cats were likely stopped up.
As to the air/fuel: low to mid 13s for dyno
Numbers, high 12s for going down the track quicker.
Use your fuel trims (int & BLMs) for idle & part throttle.
Use the wide band for WOT only. Multiple reasons, been covered many times.

 

Awesome good to know and yes I was only going to use the wideband in PE wot mode.

Thanks!

Here's a clip of the car!

 

There was a small exhaust leak you can hear at the end I fixed it though!