I'm getting a code 22 (Vtec pressure switch). I also have a code 91 (FTP low voltage), that's because my 96 dx doesn't have a FTP sensor and the 98 P72 ECU is looking for a signal from it. Those are the only two codes that I'm getting. I don't think they would cause me to be in limp mode. I don't remember what speed I was going when it didn't engage. But I know for sure the I get a rev limit at 5000 rpm. Really strange.

Would a dirty oil screen cause this kind of intermittent problem?

Maybe I should just change the entire Vtec unit.