EGR Valve Question - P0403

Hi,

I got the P0403 code for a few weeks now, on my 2001 LS v6, and it keeps coming back after I erase the code.

I took the EGR valve off today and sprayed Seafoam on the the holes, and then wipe them off with paper tower. I don't know how to test if it is working fine. But after I put it back, with new gasket, the engine lights came on again after 4 or 5 starts.

The EGR valve doesn't look very dirty to me, but my car has 165k miles on it. Is there a way to test if the valve is working or anything else I should check?

Thanks,
...
ling

Hi,

I guess I should just post an update.

I ended up ordering MD367540 and MR126976 and replace both of them. After 1 week of frequent driving, the light hasn't come back. And I passed CA Smog test.

Changing the parts wasn't hard at all. The three nuts weren't too hard to remove. The tubing was kind of tricky to get removed without damaging them. But 30 minutes was all it took for me, who hardly work on car. I have a '01 LS. They sit on the left (from front) side of the engine.