wildstang87

100% true, but to add to that, i will say again that the lowering fuel pressure wont change a/f ratio. neither will raising the fuel pressure change the ratio. the computer takes all responsibilities of the a/f ratio. the purpose of the regulator is to keep the pressure low enough to not cause any problems at idle and to increase the pressure as engine load increases, not when a/f ratio is off.

TMC

I've never used one and been happy with that but you need to have a good MAF, generally not meaning the C&L IMO.