Chris drop down 2 posts and look at performance mod post, as a 99 from my experience not much gain over stock program with a computer reflash which is what you will have to do with OBD 2, OBD 1 PCM has replaceable chip read thru the performance post and if you still have questions repost them.
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
A forum community dedicated to Chevrolet and GMC diesel truck owners and enthusiasts. Come join the discussion about duramax engines, performance, builds, modifications, classifieds, troubleshooting, maintenance, and more!