I have a 98 honda civic ex and I was wondering why my vtec doesn't respond when I reach high RPMs. What would cause this?

 

Are you throwing any codes?

Is your oil level right?

Also maybe it is hitting VTEC, but because it's single cam it might be harder for some to hear??

Also, use the search feature on this site to help find problems like this one. Here is a thread that might help you:

https://honda-tech.com/zerothread?id=164863