Hi Alan,

I recently had a Vortec in with a stuck poppet on cylinder 7. Gas readings at warm idle were HC 392ppm CO .33% CO2 13.3% O2 1.37%. After unsticking the poppet HC 0ppm CO 0.05% CO2 14.0% and O2 0.14%. This lead me to believe even though the poppet wa... Login to read more.