Car was sputtering on highway, now worse, driver relays clic

[jt15833]

A few days ago I had some sputters and hiccups on the highway, thought nothing of it, although it was a new issue. Then I went over a transition on highway and it seemed to coincide with that so I thought it was physical (ground or sensor wire maybe).

When I started it today, the relays at the driver footpanel were clicking very fast, and when the ones down by the ECU started clicked the car died. I don't think it's the relays themselves, because even if I swap them around, they still click, very fast. It seems either ECU related or power supply related. What are the ground wires to check?

I pulled the codes, getting

14 - speed sensor
34 - knock sensor
41 - intake air temp
82 - crank position
105 - EGR

all these are correct except crank position, which I've read is monitoring only. The other sensors actually are missing for the most part.

It's a 95 S14 with a 3C ECU and pretty stock KA24DE. Fuel pump seems to be priming and running okay. Everything under the hood still looks tidy although this could be a grounding issue. No multimeter available to check battery/alt status, I'll work on that.

Any advice very welcome, thanks in advance.

[Lobo240sx]

Reseat the ECU and check the battery terminals.

[jt15833]

Did this and it worked for a little but the problem came back quickly.

I drove it around town and I can fight the dropping RPMs by revving the gas until a certain point but if it wants to die it will die. The last time it died pulling onto my street and the battery and brake light illuminuated, don't these two together usually mean the alternator could be bad?

[Lobo240sx]

Get your alternator checked at a O'Reilly's or Vato Zone. Only problem is if the test comes back good, it might be due to no load on the alternator. The voltage regulator could be failing.\

Check all grounds.

[asoomal]

Has to be a grounding issue, never seen so many codes at once.

Also check the ECU pins for any dirt or corrosion.