I recently put some headers on my car and while it was down I sent the PCM out to Solomon for a basic bolt-on tune. Before the tune, the plugs had a nice tan color to them. After running a few hundred miles I pulled the plugs out and they are as white as the day I put them in. I'm not getting any knock according to the knock detector on the TorquePro app. Is this normal? I don't want to burn it up running too lean.
