Cel light/ limp mode

[Awsomsauce]

I have a p06 board converted to p28, s300 v3, all parts purchased and installed by church. Car recently received an engine swap d15 to d16 vtec. Car is throwing a cel after a few minutes and the jumper on the passenger side kick panel isn’t showing the code when I jump it. (No blinking cel) Also the s300 stops live function and doesn’t register an error code or trouble code when the cel kicks on.

Key on engine off, all systems normal
Key on engine on, normal for a couple minutes then high idle and cel

The tune is the p28 base map available from the basic tunes in the software.

Aem short ram
eBay headers
Custom exhaust
92 civic eg manual
Recently replaced dizzy new (car ran fine for a week after)

IACV and throttle body is bypassed and removed from coolant system.

[Spunkster]

What is the serial number that is on the s300 board inside the ECU?

Are you using resistor or non-resistor type spark plugs?

[Awsomsauce]

I’d have to take the ecu out of the car, the spark plugs are ngk stock from Autozone

[Awsomsauce]

Good news! I figured out what the cel most likely was. The IACV has a hole in front of the throttle plate causing a high rev idle. Since there’s no coolant to alter whatever witchcraft happens in there it doesn’t read or run right.

Resolve; JB Weld to the rescue! Plugged that hole, idle is cherry and car runs smooth as it did before the swap. Thank you for taking the time to resolve my issue guys.

Hondata still the best!