Since I put this new air filter in, I noticed a few times when setting off from traffic lights and round abouts I was loosing power. E.G. Instead of setting off full throttle and getting to about 15 mph in seconds its taking ages to get to 10 mph then it starts to pick up properly. It only seems to do this once its warmed up or been on a long flat out drive from cold. So last night I put the original Air Filter back in and I thought it had cured the problem, but just at the last set of traffic lights on my way home it did it again! Any ideas?