Hello, I have a 99 Accord lx 4 cyl vtec and have started having some problems. it has 108,000 miles on it. It has started kinda doing a stutter type vibrating when you are around the 40 mph range and when the engine is kinda lugging just before down shifting. if you press the accelerator on down it will go ahead and down shift and it stops. I have replaced the plugs,rotor cap button and ran a good bottle of injector cleaner thru it but hasn't changed . I have not replaced the trans fluid yet but I have replaced timing belt and water pump at 100,000 miles. Any suggestions and help would be apreciated. Thanks Krusty