Ok so I am looking at buying a 1990 N/A 5spd. The check engine light is one and the guy doesn't know why it is on. Is there any way to find out what code it has so I know what I need to replace if I do get it.

Also the guy says that it runs fine but it doesnt stay fulling under full throttle. Any ideas???

 

Here's some info on checking the codes on S5 RX-7s. All you really need is a piece of wire to ground the check plug:

http://www.banzai-racing.com/FD&S5_error_codes.htm

...or this site, which has a helpful photo for finding the green plug:

http://www.1300cc.com/howto/how2/codes.html

 

Yeah...the built in code reader does a pretty good job !