98 ZX2 cuts out when running and slowly dies

[blkhole]

My 98 ZX2 has a lot of modifications:
Superchip, Cold Air induction system with S&B filter, UHV plugs ,wires and coil, centerforce dual friction clutch, strut bars front and rear, 4” exhaust and Borla muffler, Two 2200hp front axles instead of the standard three, Body kit, Eibach suspension pack, crossdrilled brake rotors and ceramic brake pads, and numerous other small modifications. I have had 10 years of problem free running and racing from this little trooper until this one popped up and this one is really screwing with my head!
I would appreciate any help and if Zefyr and Markb873 want to pop in they will be welcome. This sounds very much like the problem Zefyr has.
This started about a month ago out on the highway, going along and suddenly loose power like someone shutting the ignition off. Then rough running and coughing and a series of burping backfires then just dying away to stall. No MIL light indication. I turned the key off then back on and it restarts like nothing was wrong, I guess it resets? Two weeks later it starts doing this again so I take it into my mechanic. He can’t make the car do any of this. I go over and take the car out of the garage for a run. Belt it for 15 minutes and there it goes again, this time we get a MIL with a code of P1112 (I think that’s what it was) something about the MAF and the TPS giving garbage readings to the computer. I notice that at idle the rpms are fluctuating between 780 and 3000 rpm. This is usually caused by a sticky TPS switch. Changed the TPS. This worked for a week. I was out for about an hour and I’m just heading home in city driving, it just starts to fade away and in the end I just have enough momentum to coast into a parking lot. Turned the key off then on again but this time it started rough. Turned it off and then just turned the key on, didn’t try to start it and noticed that the MIL was flickering and I could hear a clicking from inside the engine compartment. Had a look and found that a relay in the ECM box was chattering, the MIL light was flickering in time to the relay chatter. Had it towed to my mechanic, it took him three days to get it to do the same for him, at least he knows I wasn’t Bsing him now. Replace the ECM relay box ($380) this is starting to hurt!
This works for one day then the new ECM starts chattering again. Put the old box back in and get a refund for the new box, Guess its not that.
This is definitely starting to look like an electrical problem and not mechanical. As I have a superchip installed that’s the next place to look. This weekend …remove the superchip and see if the original chip in the computer works ok. I really don’t want to buy a new computer at nearly $1000. If anyone out there has any ideas about what this problem could be I would really like to hear them. Also if anyone needs installation information on a modification, I have a large data base of mods and install sheets for the ZX2.