I have a question that I hope y'all can help me with. My gs has lost power recently...like really slow. 130-140 max on hte highway after holding the throttle fora bit. I have installed an air filter. My mechanic is saying that I need a rejet because the air filter isnt sucking properly. is this true or is the mechanic trying to make a quick buck off me?
What kind of air filter did you install? If you installed a stock air filter, you shouldn't need a rejet. If you install a high-flow air filter like a K&N lunchbox or the one that fits in the airbox then you need larger jets to account for the increased airflow.