Well I can't find a time slip anywhere. I do remember that day that I had just put in a new 02 sensor. Not heated. At high boost it always shows low 02's. Right now I'm running a mixture of xylene and 93 pump gas with 18-19 lbs of boost and the 02's are 740's at the top of 3rd. This is with a JC93 chip. With 93 pump gas and boost around 16psi the 02's are around 800mv. Brand new plugs and wires. I haven't run any race gas since I replaced the 02 sensor. R.B.