i do have an exhaust leak (passenger header to h pipe, changing the gasket as soon as i get time), but i didn't think it would cause a 5mph difference in trap times. i have 11,000 miles, do you think my plugs could be shot? i checked the air filter and it was not that dirty, and i always run 93 octane. my only mods are off road H pipe, flowmaster cat back and 9" K&N filter. i just put the off road H back on which explains the sudden leak. but man, i was trapping 114 with the same combo last year, every run.