CEL Code EGR, stock driver seat slide

[dawalude]

Hey guys, I usually just browse this forum through the search function to answer my questions, but after reading through multiple archived and search results, the problem still exists.

I own a 1990 240sx with about 77k miles on it. It is completely stock. The check engine light turned on and I had a mechanic remove the head and intake manifold to clean out all the passages. I also tried some choke/TB cleaner. The prior owner replaced the EGR Solenoid when he failed smog, which temporarily fixed the CEL. Now, the CEL comes on at random at highway speeds, between 65-85 mph. Sometimes it shuts off completely, and other times it remains on. I checked the EGR valve by pushing up on the diaphram while the car was running, and the engine hestitated so I don't think it is the EGR valve. Any help?

Also, my driver side seat is very hard to slide back and forth to adjust lenth to pedals. How do I fix this problem?

Thanks in advance for any help!

[The Mic]

If you know how, perform the self-diagnostic test to erase it.

http://www.240sx.org/faq/articles/ecmcodes.htm

[dawalude]

Thanks for the site!