Hello, I've got a 2001 Civic EX. About 80K miles on it. Over the last couple of years mileage has dropped from the 33-38 range for city/highway to about 28/31. I've changed oil several times over the last year, changed air and fuel filters, and kept tires inflated properly. What should I look for next? The book says plugs are not needed until 100K, but I suppose plugs and wires are cheap enough to try. I haven't looked into EGR or PCV valves- not sure what this car has in that department. -Les