Just purchased a 95 GS300 the check engin light came on 1 hour after driving it home had the codes pulled came back with a 71 EGR system.
Had the pepboys run some test on the systme told me the EGR Valve has carbon build up.
The VSV vacume switch valve to much resistance.
The EGR temp sensor needs to be replaced.
Total for parts from toyota is $685 is there website with OEM parts for less?