so i have an 85 iroc the engine looks good but i got it checked the other day and came up with 3 codes: 24 vehicle speed sensor/circuit, 32 egr system, 43 ecs electronic spark control module.

so i want to know how and what i need to do to fix these problems the engine runs fine but sometimes smoke comes out of the exhaust when started and somedays it doesnt also not to long ago when i was coming home from work i was waiting for the light to turn green and the engine starts losing power and when it passed 500 rpm it just died later it did it again and white smoke just kept coming out of the exhaust for a while. i drove it today and it runs like it did before but when i turn it on sometimes it start right up but other days it sounds like it struggles for a sec then just starts up but not as loud.

also my car when im at a complete stop and floor it the car just starts picking up speed slowly there isnt that much power what can i fix or replace to get more power?? also my transmission when it changes in first gear it really kicks hard and pulls forward and the rest of the gears are normal but then other days it bearly kicks that hard the guy that sold it to me said it has a shift kit but i dont think it does

well thanks for any advice i really need to know what i can do to fix it up because this car is my DD and i dont want to get rid of it