Hey first time here I just joined anyway I have been seeing alot of advertisements about these so called mileage boosters,performance enhancements etc that plug right in under the dash where you plug in a code reader do these things actually work and on my 2013 C70 or will it mess up my engine ?? Any help would be greatly appreciated

 

don't waste your money. Modern computer controlled engines run at an optimal fuel trim by mapping sensor inputs. Its possible that an after market device can fool the engine into running lean which will cause the engine to run hot and can cause damage. So yes it is possible such a device can cause damage.

 

I would assume they do not.