Stallin engine

we have a 1992 Toyota Camry which runs great except that it stalls at every stop light. We have had the engine, distributor, coil, coolant tempurtaure sensor; computer, and EGR valve checked. Yesterday the mechanic stated there was nothing wrong with the EGR Valve, Any suggestions of what to check next?

Idle Air Control (IAC) valve. This valve controls idle speed.

thanks, this was mentioned and I was considering it as my next step.