I have a 2006 Nissan Xterra. After a repair, the computer was cleared of an error code but now I can't get the computer system to be OBD "ready." I followed the complex drive cycle instructions in the owner's manual to a tee over two dozen times but I can't get the computer system OBD "ready." It won't finish its diagnostic and report readiness. Does anyone know how perfect that drive cycle needs to be executed? For example, if part of the cycle is to drive 55mph for 3 minutes and you drive hit 57, does that ruin the cycle? Help! I need this car to pass state inspection.