Funny, Toyberg, I went through the exact issues with my car.
The egr valve is not that expensive. Your hot inlet pipe to the egr valve could be plugged up. Make sure they check this. Also, the early egr valves were sticky, and I think Arthur posted that the part was changed. In my case, the hot inlet pipe was plugged up, but the c/e light came on, so I replaced the egr valve. I think it was about a $200 part.
The transmission upshift delay valve is code #26, and I had this problem, too. It is located behind the brake master cylinder, and has a green and black line running to it. The green is a vacuum line, and it could be plugged up. Mine was, I cleaned it out, but the code came up again. The upshift delay valve is only about $25 and easy to replace. Arthur posted that this part was also updated.
If you can eliminate the above two items, then you may be home free.
I know your frustrated with your car like I was. I thought it would never end and I couldn't see the light at the end of the tunnel. But these things just go out on these cars, fix them once, and you'll be good for hopefully the life of the vehicle. Believe me, I feel your pain.
If it's the actuator, which go out due to a faulty wiring harness, you can also purchase the one from me.