[jeffcoslacker]

Most feedback controlled engines won't run right without a reading from the EGR. It shouldn't make it run rich. It's there to cool the combustion under hard load, and prevent formation of NOx emissions. Some motors will tend to detonate without EGR charge under load. If your motor is knock sensor equipped, it may be hearing detonation when you drop down on it, and retarding the timing or cutting back on the throttle to prevent it.

Vtec motor might have other safeguards built into it to protect it, as it involves valve timing changes, I know NOTHING about them, other than basic theory of operation.