My friend has an older Gm Trail Blazer it runs good but the Check Engine light comes on she’s on a fixed income and almost 80 we took it to Auto Zone they ran the free test and said she needs a Exhaust Gas Recirculation E GR Valve is this expensive she does not know a mechanic so I told her one we could go to not the Dealer they always Charge to much I follow you all the Time Joan Hall In Baton Rouge Louisiana in fact we are taking it in today but being on a limited income and needed it for Doctors appointment and store she does not drive it much Thanks For Your help two Scared Seniors PS I told her Scotty is the best for Advice Thanks Joan Hall