Hey everyone idk if this is the right place for it but I have a problem. Car has 70,000km.

Last night when I finished work I went to my car it started fine but then when I went to accelerate not much happened. The engine goes thud thud thud kinda sound and no acceleration it will roll up to 40km/hr and then if I hold gas just goes at that speed. I try pumping the gas pedal and hit it to the floor and nothing at all once I stop and go again it goes thud thud thud and sounds high revs for a bit but doesn't go passed 2,000 rpm after. U can clearly hear that engine knock at that time.

No check engine light no dash lights car turns on fine and stuff drove it to a Nissan dealer after checking it at CT. Awaiting results but I don't know if anyone here has any input.

Im told car has gone into "fail safe mode" as something is wrong but no check engine light flashing nothing.

Anyone have any input?