How can you tell if your EGR valve is bad? I was pushing the thing up today and it took some force. How easy or hard is it supposed to be to move it?

 

While your engine is started and up to temp, press the diaphram up. If it is still good the engine should start to die. If you hold it, it should kill the engine.

 

Whats the car doing to make you think its the EGR?

 

I don't know if all years had the EGR position sensor, but my '89 TBI car did. Above 50 mph, it would open, then close the egr to make sure it was operating correctly. It was opened by vacuum, but closed by exhaust backpressure. I'm not sure your year had one, but I would guess it does.

On my '89 I "lost" the Cats (cat....). If I was running about 55mph when it did the EGR test, it didn't have enough back pressure to close and would fail the EGR test. If it redid the test above 65 mph, the light would go out (it would then pass). Once I added the cam from a 350 TPI car, it never failed again. This is how I learned about the EGR position sensor (trying to figure out what was causing the EGR code, but only sometimes).

If it has a sensor and no code, I'd say it is very likely fine. If it were clogged, there would be no backpressure and it would "fail".

If you can find a listing for an EGR position sensor for your year, you will have a better idea if it is or could be bad.

I hope this helps.