Please let us know as I also live in California and I have not had a chance to install the EAT chip I bought a few weeks ago from them. From the earlier 2003 threads here, I read that the D'Sylva EAT chip was supposed to have no knock/ping when compared to the Dinan chip (which I currently have in my 91 M5 now). I do get slight knock/pin when throttle around 3000rpm with a 1996 Dinan chip and with the CA 91 Octane gas and no knock/pin above 3000rpm (that I can discern).