i have a 1985 z28, originally had tpi 305 and previous owner put a 350 crate engine with a set of trick flow twisted wedge heads, 350 injectors, and computer prom, with the stock 305 tpi. i just purchased the car after it had sat for about 10 years, installed new fuel pump, tank, sender, filter, and performed injector cleaning, replaced cts and wiring. the car runs great when it is warmed up, runs poorly when its cold. my biggest complaint is that the exhaust smells horribly, i assume its running rich as it will smoke a very little when start and when on it hard, but not sure where to start fixing it, and dont want to spend a fortune on it right now. would an adjustable fuel pressure regulator help, bad injectors due to sitting, should i upgrade the runners on the intake? i have no codes in ecm at all

 

Bad cat or no cat

 

it does still have the original cat, I have thought about removing it, but I don't believe that to be my issue.

 

That is one of the main issue