Hello and thank you for your post. I am a master certified GM tech, with 15 years Saturn experience,and can help you to resolve your issue.
do you know if the codes are the same as before?
if you do not know, autozone can check them for free and you can let me know
The first time I pulled the codes a year ago or so the primary code was P0404 and the secondary code was P1404. The P0405 code is new.
this code (p0405) is an EGR position sensor code
it means that the position is out of the calibrated level.
you really need a scan tool to see what the pcm is reading because you might back probe the connector at the egr valve and read one thing but the wire might be broken somewhere
the easiest thing to do if you don't have a scan tool, and you already replaced the valve is to replace the connector completely (all new wires) and see if the issue is resolved.
GM sells the connector with short wires (1' or so) that you can splice in to the harness.
While you were offline I was poking around the Saturnalia web site and found some comments and pics by "wolfman" on one of the posts. When I saw the pics and his comments I realized that carbon build up was an issue. I spent a half hour and got all the carbon off the EGR valve. When I put the EGR back in the codes were still there but my tester went from red to yellow and the check engine light went off. I assume that the issue was indeed carbon build up and that the codes will clear with some driving and I can go get my smog test. in light of what I suspect is a fix, my question to you is what can I do to slow down the carbon build up and what do you think the cause might be?
I thought the egr valve was new?
carbon build up in the passage or in the valve?
if the buildup was in the passage, that just needs to be cleaned out when replacing the valve but not a maintenance type of thing.
that builds up normally in the course of time because exhaust gas is routed through the valve and that is what you would find in the exhaust pipe.
it does build up. Usually in the valve but sometimes in the passage.
I wouldn't worry too much about the build up coming back
there was a reflash available on some Saturns to allow that build up to form without setting codes but I don't think 2001 had that reflash available.
It was interesting I just went to the store - where I am that is 20 miles. And the light came back on. I am still thinking it is the EGR and carbon. That valve has been in there about a year with heavy mileage (30K or so). When I first put it in the problem went away. I am going to take this one out and soak it some more - if that does not get me a smogable car I will buy another EGR since it does seem that we are on the right track. Appriciate your help - and any other thoughts you might have to help me out.
Do you know if I can un screw the valve plunger and take it out and clean it and also where the valve seat is?
I have never taken one of those apart. I don't know if it will be ruined if you take it apart.
I have cleaned the passage in the intake manifold with a shop vac and a screwdriver, and as for the carbon in the valve itself, compressed air and a screwdriver to clear it out.
the valve opens (unseats) by moving up and down. when it is down, it is seated by blocking the flow of exhaust gasses.
the more open it is the more will flow.