Hondata

2003 Acura RSX w/ k24/k20 engine.
PND ECU w/kpro v2.0
only mod is injen CAI

The car got tuned about a 2 months ago. Ran fine afterwards.
about 2 weeks ago, i got a CEL. I went to read it and it said there was 1 code. but When i actually looked at the code it said there was nothing. I turned off car and reset code. Started and everything was fine. This happened a few times. Then last week it did it again i could not reset code, and drove it. Noticed it was in limp mode. stopped car. Tried reset again and suddenly it was fine. Then i started noticing i was getting a flickering CEL, but when i datalog there was zero knock. If i drive car it seemed normal, but was not consistant. Sometimes car would have it sometimes not.

Then this morning i went to start car and the dashboard lights went bonkers flickering, and the gauges spun erratically. The car would not start. Would not even turn over. Turned key, lights and nothing.

Where should i start on troubleshooting this?

It sounds like you either have a wiring issue in the vehicle, or your battery is low.

I'll check battery, seems the most likely culprit.
The wiring, I have double checked all of my grounds already. The wiring harness is not modified at all. I'll double check all my plugs as well.

So I checked my battery and it was at 12.8 bolts after sitting all day. I double-checked all of my connectors on the engine and didn't notice anything lose or odd. I put my stock prb ECU in and the car is not having the same symptoms. Is it possible it's either the ECU or kpro?

You need to check the battery voltage at the ECU when cranking using a multi meter as that is when it will drop significantly.

Do you happen to know which pins?

Also it came back on my stock ECU. A solid cel. P600 and a lean bank code. (obviously lean bank due to stock ecu)

pin A2 for power and Pin A4 for ground.

Ok, when i turn the key to accessory I see about 11 vdc. When I start the car it dips to about 9-10 vdc, and when it starts running its seeing around 14 vdc. Think its the battery?

Post your calibration as well as a datalog of when this is all happening.

Ok, i attached my cal, and the two datalogs when i was pretty much idle and was getting the flashing CEL

I would recommend taking it back to the tuner at this point as I cannot see anything from the datalogs indicating an issue. You could even have short in the wiring somewhere that could be causing this.

Thanks, I'll see what he says. Sad thing is it's so intermittent. Didn't do it at all today

Which is all the more indicative of a wiring issue.