So I installed a S2 IM, ITR cams and stock unchipped USDM ITR ECU in my buddies 98 GSR. Figured this setup is close to an ITR and won't need a tune. Anyways, after the install he got a CEL P0453 and a P0450. Both pertaining to Evap solenoid if my scanner is right. What would be causing this CEL? I have the evap solenoid vacuum line T'ed to the PCV valve vacuum line which is getting vacuum from the nipple at the top front of the S2 IM.
On the stock GSR IM, this Evap solenoid vacuum line has it's own dedicated vacuum line connected to the intake manifold.