Sakkie

I have a 1999 Saab 95 and experienced a sudden loss of power after accelerating - black smoke from exhaust and extremely bad petrol consumption - 20+l/100km.
After a couple of ks the car started miss firing
Visited dealer and Tech showed codes P0171 & P1171, indicating lean mixture

The car idled fine and accelerated reasonably up to about 3000rpm with max 3500rpm
With maximum acceleration (TWO) no power

Changed and replaced in sequence -1. Air Mass Meter - no difference, 2. MAP sensor on intake manifold - no difference, 3. Air Intake Sensor - no difference.

Did thorough check of all pipes - no leaks
Checked turbo - everything fine
Checked petrol pump, petrol filter and injector rail pressure - no problem
Checked plugs - black and badly fouled
Replaced plugs - miss fire stopped but returned after a couple of ks
Visually checked catalytic converter and it looked fine - BUT THEN WHEN WE CHECKED THE AIR FLOW THOUGH THE CATALYTIC CONVERTER WE FOUND THE PROBLEM.

The catalytic converter blocked the airflow which stopped the turbo from working.
We replaced the catalytic converter and immediately everything was 100% again