Sheldon Samuel

Hi all, I have a 98 r34 gtt and I drove it the other day after letting it sit for about a year and I can hear rattling when accelerating, it backfires when my foot is off the car, my engine light turns on when im going about 80kms and sometimes the car just loses all power and shuts down when driving. I've recently gchanged my turbo gasket because it was shattered. I dont think that's the problem, honestly I have no idea. Anyone please able to help me!!