The check engine light lets the operator know that a fault has occured in the Emissions system and it has been detected by the diagnostic module.
So, the ONLY way to start diagnoses is to get the codes from this module. That is all the ck eng lite is trying to telling you .
There can be upwards of 60 codes and then they have to be
interpreted. [ the tricky part]
Do not change a part on your car cuz someones else tells you there light went away when they changed part "XYZ".
You will run out of Money.....