Okay so i already feel stupid for asking my question before researching, I’ve come to the conclusion that it’s detonation. Not sure why it would only happen in first gear but glad I’m catching it now. I only ever use 93 octane and the only mod to the engine is a forge bov, stock tune, never turned up the actuator. My intercooler is dented, but it’s not running any hotter than usual. I feel like I can’t just put some octane booster in and forget about it. Why are the main causes for detonation and how do I eliminate it? Thanks again.