help? engine breaks up when in boost
 

just got done swapping in a jdm 7mgte motor, everything is fine but when i go to boost it it just breaks up like it just hit a brick wall...it wasnt doing it the 1st couple time i boosted it but now it does...also getin code 51 and the light next to the temp gauge(looks like a building), what is it it stays on...
is it leaking boost? any help would help

lock it up...fixed it...my lower intercooler coupler blew

Light next to coolant temp is supposed to be a radiator. Means you're low on coolant. If you don't have any coolant in your overflow reservoir, that light'll turn on since the sensor for it is in the bottom of that reservoir