i have a 1997 subaru legacy outback, i recently had my car put on a scanner from auto zone and the code for the egr valve had came up, the only code that shown. i bought the egr valve and replaced it and the engine light went off for about a week and then all of a sudden came back on.. i cant figure out why it came back on.. any solutions??

EGR valves hardly ever go bad on these.

The problem is usually either a vacuum leak, or the diaphragm in the Back-Pressure Transducer valve is ruptured. BPT valve is the black plastic cylinder next to the EGR.

Most of the time you can get a good one used for cheap at a u-pull junkyard. Otherwise, its a dealer only part as far as I know.

It is also possible, if the car has very high mileage, that the passage in the intake manifold from the egr valve to behind the throttle body is clogged.