[cbaber]

P1399? No mention of that code anywhere in the factory service manual. The flashing CEL means a pretty critical misfire situation. Obviously the Ultragauge is giving you some weird codes, and the mechanic didn't pull the correct code either. (If it's not in the Honda manual I don't see how it's the correct code)

Go to any auto parts store and have them read the code to see if you get anything but 1399.

If you aren't noticing a rough idle, or studders while driving, it's probably ignition related since it is effecting all cylinders and not just one. Start with plugs, wires, cap/rotor. If you did that, I would try ignition module inside distributor (did you order a new distributor??? Expensive, but it will replace what I just mentioned). If that doesn't work I would borrow a fuel pressure gauge and test fuel pressure. Check the timing as well. If timing, fuel, and ignition all check out, you might be dealing with compression problems. Could be leaky values or piston rings. But start off simple and work your way through it system by system. You don't want to be throwing parts and money at it without checking the right things first.

Oh I almost forgot, like yoyo said check all your grounds before you start buying any parts.