s13 (ca18det) problem after changing to fabric exhaust [HELP]

[2oo]

I've changed to the fabric exhaust as my MOT is up, and it's running horrible...

Went from 3" full exhaust (no cat) with 4.5" tip to the fabric s13 exhaust with catalysator and two silencers.

Video:
https://vid.me/OOxq

Can the problem be with a faulty catalysator? Like if it's dence or something?

I've tried adding and subtracting around 20% fuel aswell to the map, no difference..
The spark plugs spark nicely, all four of them, sanded them down today and this video is from after mounting them.

Shoot your thoughts and ideas everywhere as this is pretty urgent!
Thanks!

PowerFC is mapped with the 3" exhaust!

[2oo]

Edit;

it only stays alive if I floor the throttle all the way down

[davetherave]

Sounds like the air flow meter is unplugged.

[pointz]

Why you fitted a cat s13's don't require them fact

[pointz]

Sounds like the air flow meter is unplugged.

It will run smooth with afm unplugged but won't rev past 2k

[pointz]

Just listened to the vid! Sounds like a big air leak to me

Love how your wideband says poo lol

[2oo]

Sounds like the air flow meter is unplugged.

I've checked the z32, contact is in.
Ran smoothly with the other exhaust, it's been sitting for a week tho while changing but I've never had any troubles with it before

[2oo]

Why you fitted a cat s13's don't require them fact

Norway has craazy strict exhaust rules, so I'm not taking any chances.
With the new rules that came last year too, they have to notify the road patrols if they suspect any form of tuning aswell.. And they nearly cut your plates of for running a FMIC.

Just listened to the vid! Sounds like a big air leak to me

Love how your wideband says poo lol

I don't know how that could've happened by only changing the exhaust, but sure, I'll check it out tomorrow! Thanks!
Haha yeah, isn't it supposed to do that? lol

[2oo]

Small update;
No air leaks detected. I checked through the whole pressure piping, dump valve piston, vacuum hoses and the airflow piping.
Disconnected the MAF, ran pretty much the same.
Connected the MAF back in again and removed the AAC valve contact on the intake manifold. <= Had my best run, managed to make it stay alive pretty stable (with almost flooring the throttle pedal tho), however, the AFR readings were insane. While it ran like this (with the throttle close to all the way pushed in) it read something around 17.0 - 19.0 on my gauge. Then I could let of a the gas and it would hold the rpms still steady for a few seconds before stalling. The AFR readings were something around 14.0 - 15.0 (after releasing the throttle pedal) before stalling.

Any mad mechanics who got any clue?
It seems like the AAC valve plays a little role in this? Or is it just the simple fact that the map I run on my powerfc is tuned for a non-cat 3" inch exhaust so it messes up everything with a fabric exhaust?

It started to mess around after running with no exhaust on in the garage as I had to drive it up and down on ramps a couple of times to test-fit the fabric exhaust.
Can the engine or the tune take damage by this?
Running it a little on idle with a few throttle pushes using only the 90^o elbow out of the turbo as the "exhaust"?