2003 saab 93 2.0T engine code p0606
Yesterday I was driving to my friends house and I gave my car a fairly serious acceleration to get up to speed on a highway. As I was shifting in 3rd gear it felt like my car hit a wall and cut all turbo power and went into limp mode with an extremely bad misfire. I pulled over, cycled the key 3 times waiting 10 seconds between each key turn. The misfire went away but It will only let my turbo build boost to 25% in first gear, 30%in second gear, 75%in third gear, 80% fourth and 90% fifth. I checked the codes when I got to my friends house and it only said 1 code for p0606 engine module processor.
I've replaced the spark plugs with ngk iridium spark plugs 20,000km ago, dont remember the part number. Before that I've also changed the valve cover gasket and replaced all 4 coil packs 50,000 km ago to the black tops. Not the yellow top coil packs it comes with.
I'm just looking for some guidance as to what I can do to fix this issue on a budget as I do not have a lot of money I'm able to put into this car. Thank you in advance for any help