I need some quick tips before I spend cash. The acceleration on my car is terrible. When I take off, it lags really bad unless I floor it. I'm trying to make my 98k mi. ka last as long as possible, so I don't really want to have to do this. My exhaust sputters (I have leaks all throughout my exhaust system) and I burn lots of gas. I've changed my fuel filter, plugs, wires, oil and valve cover gasket. Any suggestions before i go get an engine diagnostics test? Thanks for all the help guys.