Well "anonymous",
It appears that people who are illiterate never get a good job or make a good income, and live a life of bad financial options like subprime loans and buy here pay here, etc.
And, you cannot "bypass" a check engine light. The light is activated by a fault code in the computer. Even if you drill a hole in the dash and take out the lightbulb altogether, the "fault" will still be there.
Used cars have problems. You will always have to put money into any used car. That is just the way it works. BUT, the loan payments have nothing to do with the repairs, legally. If you withhold payment, the car gets repo'd. That's just the way it works.
And, you always have to get any "promises" to fix something IN WRITING to protect your rights. Never just believe a salesman. That is just plain stupid.
So, it is you that do not know what you are talking about regarding cars.
What is a "machinic"?? Did you mean "mechanic"? What is a "vechial"? Did you mean "vehicle"?
You lash out at someone giving you sound advice, but you bring your problems on yourself, and can't see it.