A 98 civic... You're in the wrong forum bro

If you hadn't mentioned that the car ran fine before, I would have thought that it might be a timing or cam issue. Does your car lope at idle? Not as much power at lower RPM?

I'm going to take a stab at something. I don't own a vtec engine, but I gather that the vtec is switched on by the computer. Is it possible that vtec could be continuously on? If so, that would explain it. Since the vtec is activated at a certain RPM, does the ECU use the same sensor as your cluster tach?
And, if anybody can tell me why my vtec suggestions are totally stupid, please learn me. i like to get learned.