Frustrate and need a little help!

This past weekend I took on the task of changing my lower intake manifold gaskets on a 2001 Astro. Put it all back together now I have DTC codes p0122 TPS sensor, p0405 Egr flow, and P1345 ign system or misfire??? Sure, I had all this stuff off, but I just simply put it right back on when I was done - before this job I had no codes. Van seems to run fine, but I do think it starts a little funny now. No excessive cranking is necessary, but it seems to jerk and shudder when it starts, and it never did before. Is it possible something moved and I put the distributor back in wrong?? How can I line things up and check? What else would cause these codes to just show up after a job like this? Any help would be great!

Fixed my problem. Distributor was off by one tooth, no codes or SES light now.

Glad you figured it out. In the future, this is how to align the distributor: http://files.automotiveforums.com/gallery/showphoto.php?photo=51302