Toyota Repair: auxiliary emission controls, toyota camry, egr system

Question
I have a 1997 Toyota Camry the check engine light comes on and the code is P0401 what do I need to check

Answer
This code is for an EGR system malfunction, in most cases the EGR modulator valve that sits on top of the EGR valve is the problem, remove the plastic cover and check the fiber insert for burned spots, if so replace the modulator valve as well as the EGR vacuum switching valve(VSV)