S300 Only Working When Plugged to USB

[Abe_Aponte]

Hello,

Ny S300 was working flawlessly up until a couple days ago. I'm running a P75 ECU and recently added vtec components to the board. Now the car sputters and dies on me after running good on initial startup for a minute or so when it is NOT plugged in to my laptop. When plugged in to my laptop via USB everything works with no issues. I did some digging here already and checked all my grounds and everything is good. I haven't seen a solution for this, Any idea? My S300 serial number is (57148)

[Spunkster]

Send a picture of what you have done to the ECU. Do not continue to drive it with the USB allowing it to work as that will burn out the s300. It sounds like it is grounding through the USB port.

[Abe_Aponte]

I have attached 3 images for you to reference on what was installed. These components were bought from HAMotorsports and I followed the directions the provided.

[Spunkster]

You need to check all the grounds in the engine bay.

[Abe_Aponte]

Issue solved! I removed the grounds and cleaned up where the wires make contact. Car back to 100% thank you Spunkster!