Hello,

I have a 95 Previa S/C 186K. The check engine light came on code reads PO401 bad EGR. I found a factory EGR online for $149. The engine sputters when getting on the gas or driving up hill when using regular unleaded. But it runs perfect when using premium unleaded. My van has already passed emissions. So my question is will it harm the engine if I do not replace the EGR and continue to use premium fuel? I had a 93 MR2 non turbo reading the same code and drove it for a year with no issues. Thank you in advance for any advice you can give me.