Boboutside

Thanks for the advice. I will double check that as well.

Need help. I have a 2020 Silverado 1500 5.3. I have a strong exhaust smell coming from the vents and also in the engine compartment when not driving or driving slow. Checked with a carbon monoxide tester a friend had from his firehouse. Seems to be at high levels passenger side of the engine. I’ve had the exhaust smoke tested 2x and went as far as installing a new exhaust manifold on the passenger side. The problem still exists. No visible signs of a leak. No warning lights or codes. Can anyone out there help? I’m already in over 1k and frustrated. Truck runs great at 88k and no loss of power or rough idling.