I have a 96 prelude and my CEL reads vtec malfuntion...it always comes on in 4th gear after 5,000 rpm. one mechanic say its either the vtec solenoid or the oil pressure switch...I replaced both of them brand new from the dealer and the CEL still comes on....so any advice on what else it can be??

 

Check the oil pressure - and not the switch.....

ALso, I think the vehicle has to be under a certain load for it to come on.

 

Check your oil often. I used to have a similar problem. Sometimes my Vtec just didn't kick in. I found out that my prelude was burning a lot of oil and when it got low my check engine light would blink and Vtec wouldn't work.