Check engine light flashing 99 blazer

SOURCE: 99 chevy malibu alternator?

That is a very good place to start. You and remove the alternator, and most auto parts stores will check it for you.

SOURCE: Engine misfire, EGR replaced still rough idle!

First, check the passageway to the egr valve to make sure it is clear (often plugs up with carbon) second, make sure that the egr control is working. Also a good idea to have any codes checked and old ones cleared.Computer may need to cycle a few times to "learn"new parameters.
In general, it is good to shut down your engine when check engine light comes on...The next step after that is to determine why the light came on.
If the cause is an oil related or coolant related item, you should drive no further 'till it's corrected...However, there are numerous sensors that can turn it on with no disasterous results if you continue to drive One example is the light coming on because a gas cap has not been put on correctly...On many vehicles this will turn on the light and set a code, but the car will suffer no damage if you drove to your destination before correcting it.So, if the light comes on and it is not overheating and you have good oil pressure, and you hear no noises from engine, have it looked at but don't put yourself in danger on the side of a major highway for a nonsense code.
Most major parts houses will read codes free...take advantage of that service and get yourself a basic repair manual, so you have an idea what all the stuff under your hood is and does.
Good luck with your car!!

SOURCE: Car stalls when idling at stop light

have the car checked when the check engine light is on,also a good scanner will be able to give you the history codes,get back to me with the codes and we'll go from there. you need someone with a professional scan tool

SOURCE: P0300 code reading on Chevy aveo. Engine light

Pull out your spark plugs. Change them if dirty. There might be a problem with the fuel trim, thats causing spark plug to foul up prematurely. A stucked open EGR valve can also cause a multiple mispfire code(P0300) but then it would be accompanied by an EGR code(P402) which means excessive flow detected. Anyways if was indeed a fouled up spark plug change them as well as the air filter.

SOURCE: 2007 Chevy Silverado when my check engine light

It's a safety feature. For example, if there is no oil pressure when you start the engine, you could not see that unless you were in the car and could spin a bearing or seize the engine by starting it remotely and letting it run unattended. So when the check engine light is on, there is something not working properly with the engine/engine management system and it wants you in the car where you can see the guages and turn the engine off immediately if there's a serious problem.