The car is a 1994 Honda Civic Dx Coupe. I have a check engine light on and the vtec is off or broken. The code is for a vtec pressure valve, what and where is it, how hard to replace and does it usually need replacement in these kinds of cases?

 

Check your oil level first. If that's ok then I would replace the switch
Located right buy the distributor, green plug end
(sorry for the big pick its the first one I found)