Back of the engine under the throttle body on the drivers side. That plug is for the oil gallery. The other one is a knock sensor. Do not remove the knock sensor. A good quality sandwich plate shouldn't leak

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Marti


Car: C Red S13 Silvia 2.3l 400+rwhp-SOLD
Daily ae82 4age corolla (light mods)-Sold
Daily:SWB GQ Patrol
Will be a 03-04 STI next