Toyota Repair: 90 Toyota Corolla AllTrac, modulator valve, toyota corolla

Question
My wagon didn't pass smog today. the guy said my timing is off and EGR valve wasn't functioning correctly. I can get the timing fixed by my husband but the valve is over 200 bucks. Is there any way to clean the existing valve? is there a module that regulates the valve that might be cheaper. If I fix both things (timing & valve)is there a pretty good chance I will pass the retest. I have to admit the engine light has been coming on then going for the past couple of months. Thanks for your help

Answer
EGR valves are seldom the problem on toyotas, in most cases the modulator valve that is attached to the egr valve is the cause, remove the top plastic cover of the valve and see if there is a burned area on the inside of the mterial, if so replace the valve, if not then the egr passage in the intake manifold may be clogged up with carbon and needs to be cleaned out, in that case the egr valve has to be removed as well as the throttle body and the egr passage can be cleaned with a stiff wire at both ends.