Can a faulty egr valve cause white smoke from the tailpipe on a gas engine at first start?

Yes, a faulty EGR (Exhaust Gas Recirculation) valve can contribute to white smoke from the tailpipe on a gas engine during initial startup. If the EGR valve is stuck open, it can allow excessive amounts of exhaust gases to enter the intake, which may lead to incomplete combustion and the production of white smoke. However, white smoke can also be a sign of coolant entering the combustion chamber, so it's essential to diagnose the issue thoroughly to rule out other potential causes.