if the car cuts out the same way up top off the bottle and at lower rpm's then you may have a problem with the module attached to your coil... i forgot what it is called but if it is fouled it can cause the car to screw up at high and low rpm ranges. If i were you i would get an msd blaster coil, replace this chip, and maybe even get one of those spark enhancer things... this may or may not be the problem but upgrading ignition parts like that is deffinately a good thing to do with nitrous.