EDIT: (CODES) Power Loss After Swap.
 

EDIT......WE HAVE CODES. P000A AND C1201.My son totaled his '16 FRS so we bought a salvage auction '13 FRS to repair with the usable parts from his wrecked car. The '13 was completed and he loves it.....until last weekend when we swapped in his '16 motor because of the mileage differential. He states a loss of power from the '13 engine and I concur....it's noticeable. I swapped entire engine from flywheel to intake....harness and all. I did not swap the ECU. The engine did not appear to have any mods aside from the catted header and aftermarket exhaust. After swapping his stock exhaust onto it to pass smog it was swapped back after. I assumed at the time there was no tune in the ECU or it wouldn't have passed smog????? I had a few codes for camshaft position sensor after the swap but that was investigated and found to be a broken sensor plug from the car accident. Replaced it and now the engine is free of codes. Runs fine, smooth idle. Noticeable power difference between the two engines and it now hits the rev limiter at 5500 RPM well below the red line of 7500 RPM. Both engines were manual trans. Would a tune in the '13 ECU make this drastic of a difference to the '16 engine? I was considering swapping the intake, injectors and harness over from the '13 to the '16. Thinking maybe there were possible injector upgrades??? Both engines had stock intake air boxes. I have engine knowledge but my tuning skill is zero. Any inputs or suggestions are greatly appreciated. I read that this swap was plug and play. I didn't swap the ecu because I assumed that it wasn't necessary and didn't want to hassle with coding a new VIN. Help!?!?

Newer engines have different coil packs, I don't know if that would make any difference.

Something to consider....thanks for the input!

The 15' and up coil packs only work with a 15' and up harness unless you use an adaptor kit. The plugs are different. Pre-facelift you could mix and match engine/harness setups. I think there is something else going on here. No codes?

No codes. There were codes for cam and cam sensor but that was due to connector broken off from the accident. Once I replaced and cleared codes it did not return. The rev limiter at 5500 rpm is the strange one to me. Sitting in neutral it kicks in at 5500 rpm and when under load my son says it just tops out at 5500. I have a call out to the last shop to do work on it. He said if he has the car in the database he will let me know what had been done to the car. But I had it smogged and it passed prior to the swap so I'm pretty sure it doesn't have a tune. In CA the tune must be stock. It has a slight vibration at idle but nothing crazy. Maybe a bad mount as I used the ones from the wrecked car. If you were just driving around town you would hardly notice but spirited driving reveals the lack of power instantly. Almost like it's starving. doesn't run bad....just makes more noise and doesn't go any faster. Is the pin out the same for the two harnesses that connect to the car?

swap the ecu to match the engine

Considering it.......but the hassle of coding the VIN and security features have me thinking it's my last resort. I have the equipment but I dread it.

Could be a throttle body calibration problem. I've read that to sync the pedal with the throttle body you cycle the pedal floor to wot 5 times with the ignition on. Never had to actually try it my self. And/or if the old tb isn't damaged, you could swap them.

Going to try swapping the coils, intake, injectors and harness and see what that does. injector module also.

If you are swapping back to the 13' coils you will need to use the 13' engine harness too. If you mess with the direct injectors at all be very careful as the seals are a bit delicate. I don't think these items are your issue though.

lol "a bit"




I'm with No. Something else is off kilter. Swap in your ECU. Starting with MY 15 they reversed the polarity of the camshaft tone wheels. While I'm not sure that it matters, it's the only functional difference at play here.

I am assuming that one of these codes is causing the other. Engine is 2016, ECU is 2014. Do these cars need a tune to run unequal length headers? Thinking maybe the 2014 ECU has a tune? Could there be incompatibilities with the 2016 vvt solenoids and the 2014 ecu? I know the solenoids have a different part number form 13-15 and 2016. Three of the vvt solenoids are new and the code is generating from the only solenoid that was not replaced. Going to swap sides and see if the code follows the old solenoid.

Did you sort this out yet? After a tuning session, my FRS started bogging down like you described. Bad primary cat. I'm guessing the extra vibration from high rpm pulls loosened the cat material. It was an aftermarket header/cat. It took several drive cycles for the ecu to finally correct itself once I knocked the cat out.