i bought this 1988 tran am when the car gets warmed up the service engine soon light comes on and stays on but when you first start it up it doesnt come on didnt know if there a problem or not a mechanic told me you could spend a lot of $$$$$$ trying to figure out whats causing it to come on..

 

Most of the time it is nothing to be worried about. Unless the car is running bad or to rich i wouldent wory about it.

 

i wouldnt ignore that light. its not going to explode but it isnt going to run right and your fuel millage most likely will suffer. do want to spend more in fuel than nessary? ignoring that light is a good way to do that. good to autozone and pick up a hanyes book. i know you say your not a mechanic but one of these books will go a long way to discover whats wrong with your car. there is a diagnostic section that will tell you how to "scan" your car without using a scanner. all you need is a simple piece of wire. jump the diagonstic terminal to the ground terminal, this will flash the check engine light. count the flashes you'll get your code. code 12 tells you your computer is functioning properly, this code is normal.
this will flash three times, and your trouble codes will follow. with these older model cars it is usually something simple, 20 bucks for an oxygen sensor for example. or 50 bucks for a MAP sensor, 50 bucks for a Throttle position sensor. these are just examples im listing. newer cars are much much more expensive to fix. oxygen sensor might be 75 bucks MAF(mass airflow sensor) can be as high as 150 bucks. this sensor took place of the MAP sensor used on older cars. older cars are much simpler and easier to fix and many of the parts are much cheaper. unless you are willing to except reduced performance, poor fuel economy, and poor emisions i would look into fixing your problem. it may not cost too much to fix and you will save money at the pump. you may not be a mechanic but it doesnt hurt too learn(if your going to own an older car its almost a requirement, i generally dont pay shop labor rates, i wouldnt be able to afford owning a car if i did)