so my check engine light came on randomly, and nothing felt wrong in the car, but i wanted to make sure, so i took it in to the shop and had them do the scan, they told me "it was a problem with the system that recirculated the exhaust through some kinda filter that further cleanes the exhaust and makes the car less efficient, but he said the only effect is a slight gain in horsepower (unoticable)

should i be worried about this

sorry i dont know many technical terms

and my spelling sucks

 

Gain in horsepower? is there a downside besides the check engine light?

 

To simplify the explination, it's the EGR system.

 

And the EGR system is to make the car slightly more fuel efficient as well as cutting down on emissions. It doesn't (or shouldn't) increase your horsepower. The EGR gives your engine to burn the fuel that didn't get caught the first time it went through. that also allows those bad little fumes to be caught properly by the cats.

Engineers wouldn't hook up something like that to make the car less efficient. But, I see where the mechanic was coming from. When it's not working you will get an insignificant amount of HP freed up, your fuel economy will go down, etc etc. But who cares, you got free hp!