Can you just plug off an egr valve?
On One Hand: It Might Cause ProblemsYour engine’s exhaust gas recirculation (EGR) valve opens a small channel between its exhaust and intake tract. Those recirculated exhaust gases help to reduce nitric oxide (NO) emissions and help to control detonation in some engines. Removing or plugging it will result in elevated levels of NO (meaning you’ll fail an emissions test) and may lead to detonation (“knock” or “ping”).On the Other: It Should Be FineWhile those hot exhaust gases do help emissions, the fact is that anything but cool air and fuel in the cylinder will cost horsepower and fuel economy. Disconnecting or removing the EGR on most vehicles usually won’t hurt anything, especially if you switch to high-octane gas.Bottom LineIf you do disconnect the EGR, keep an ear out for detonation, which if left unchecked will eventually destroy your engine. If you hear any detonation after switching octanes, you can simply reconnect the EGR valve.
