Fatt Matt

okay so i thought i fried my computer (in a 96 cherokee sport w/ a 5-speed) so i went to the junk yard and got one it worked fine, but there was a check engine light on. I ended up putting a ignition coil in it because it wouldnt start. I went to get an inspection and emission test and it says i have an egr valve code but my jeep doesnt have an egr valve. I cant get it to pass because as soon as its cleared it comes back on. I really need help because i dont know what to do. The jeep dealership by me told me they dont make computers anymore so i am in a bind. Any suggestions?