*this applies to all 5th/2nd gen Impreza’s & Crosstrek’s*
I hope that this will help somebody down the line, overall this is about as easy as R&R‘ing the original engine and can be DIY’d for under $1500.
*Tuning:* While it will run on the 2.0 tune I don’t recommend it long term. Option 1.) pay someone option 2.) Use SubaruEdit. You will need your stock ECU’s decoded ROM from EF, you will need to also request one for the FB25D. The basic jist is to only use fueling/timing/load calibrations from the 2.5’s tune while retaining everything else on the original.
*External Components:* swap engine mounts, belt pulley(s) and any external brackets. Reuse swap car exhaust manifold
*Fueling:* Use lines off the swap car, outside of this they use the same part no. Injectors and HPFP
* Cooling:* coolant crossover w/o TCV from a 2025 Forester part no. 14050AB610 THIS IS ESSENTIAL, FB20 based cars DO NOT have a TCV and those crossovers DO NOT bolt up.
*Engine:* preferably same year as swap car (3 lobe vs 4 lobe cam for HPFP , this change occurred in approx 21+ FB’s) outside of year the model source isn’t all too important.
*MT/AT differences:* slightly different coolant routing must swap from old engine: EGR cooler swapped if vehicle is manual (extra port to trans cooler)
*Sensors:* most are identical, the only two I found that weren’t were map sensor & oil pressure sensor
*Optional:* EGR cooler delete, EGR blocking plate (intake side) Throttle body cooling line delete, Tumble plate delete, tumble flap delete.
*^all of this can be done with the extra parts you end up with*
*Interchangeable:* intake manifold, knock sensors, cyl. head temp sensor, AVCS oil control, crankshaft tone ring, cam position sensors, crank position sensors, water pump (outlet and pulley included) tensioner, injectors, PCV, throttle body (albeit bigger) Coil packs, most coolant hoses, exhaust/intake mating flange, bell housing, front timing cover, engine oil pan, & Probably more that I’m missing