Got an unusual problem. My buddies prelude, stock h23 with plenty of mile throws the engine light if you hold a constant speed over 60mph. If you turn the car off and back on the code clears. and we cannot seem to get a code out of it. Any Ideas?

 

how are you trying to check the code? you can probably get it by having a code-reader attached to the car while driving it and waiting until the CEL comes on.

 

did u try doing this

https://honda-tech.com/forums/honda-prelude-4/diy-diagnose-check-engine-lights-4th-gen-prelude-2495089/