When I start my car it blows alot of smoke I think it's something with the choke but I'm not sure.
Any ideas what it might be it's worse when it's cold. It's a 99 z24.

A 99 does not have a choke. Cold engine enrichment is done by the computer. The color of the smoke will give you a good idea what it's coming from, so you may want to provide that so people can help you out.

What colour is this smoke? Is it coming from the exhaust.....engine bay?

Black?
White?
Blue?

Yep, it smokes when cold...but do you notice smoke during idle/driving when the engine is at a normal operating temp?


Inspect the oil level, and do a general look over of the engine. Could be a headgasket or any number or things.... Any strange smells during idle/driving?

It does use some oil...the smoke is black when first started then looks like normal exhaust should after about 30 seconds to 45 seconds. Sorry I should have been more specific the first time,and it does smell like it's running rich...I think my cat is getting bad to as I have a check engine light on and that is the code that comes up.