Toyota Repair: Codes P401 and P420 for 2001 Toyota Camry, toyota camry, p0401

Question
Hi Ted,

My check engine light has been on for 3 years now and the computer gives me the codes in the subject. The mechanic changed the EGR valve for code P401 but the light remains on. My car runs great so I am not sure about the code P420. The car has 133k miles. Should I replace the catalytic? I have heard it is very expensive to do so. Thanks,

Barbara

Answer
If you are getting both the P0401 and the 420 codes then first take care of the P0401, then if the 420 comes back replace the cat converter. The ost common problems for the 401 code are the EGR modultor valve(not th egr valve) and the EGR vsv switching valve, unless they have been replaced already I would suggest replacing both.