Can the ecm support 2 obd 2 ports?
 

I use a dash logic for my gauges which connects directly to the obd port. I want to be able to run my dash logic while scanning with hp tuners. I already tried a splitter but both cannot run at the same time. Is this because the ecm cant support both? If I ran a full set of second wires to a second obd port would it make any difference?

I'm no CAN expert, but...it depends on whether or not the dash logic is interrogating one or more modules while it is connected. There are certain messages called 'legislative PIDs' that the government requires to be transmitted on the CAN and available for reading by any old scan tool. If you're selecting PIDs in HP Tuners, you'll notice these as the green highlighted PIDs. Obtaining any other information requires interrogating a module and occupies the communication channel, so only one interrogation session at a time is permitted. Same reason why writing a file in HPT fails when the scanner is still connected. It sounds like the dash logic is interrogating modules on CAN, so I don't think it'll work in parallel with HPT.