I have a 2010 Chevy Impala LT 3.5L V6. I am It is currently stock but I am adding a Magnaflow Cat Back Exhaust system. I am wanting to add horsepower but not pay out a lot of money. I have heard a lot about performance chips, re-programming thew computer, cold air intakes, and headers. Which ones really help get some significant horsepower but that won't cost a fortune? Also ones that will not wreck the rest of the computer or cause mechanical issues. Thank you. I appreciate any help you can give!