check engine light

I drive a 95 nissan 200 sx manual. The check engine light came on recently, throwing a code 14 and 32. I have replaced both the speed sensor, and EGR valve, but the light still continues to randomly come back on days later. The car has a rough idle sometimes, and the car will randomly die when i push the cluth in to slow to a stop. But it does seem to happen more often when i have been on the interstate, or highway. LIke i said it is random, sometimes with the cluth in, it may stay at 800 rpms, sometimes it will slow down to 200-300 rpms, and go back up to idle, and sometimes it will just die. I seem to be running out of options, any suggestions would be helpful and most appreciated!

Check the O2 sensor. When I put a high flow exhaust on my car i had the same problem. Just a thought.