Engine cranks but no start, put back the old MAF sensor?

I recently swapped the engine and it worked great after its first week on the road. So I decided to do a check-up to see if everything was connected and I saw that it had a code p0174. I tried to adjust it by changing the MAF sensor and immediately after I started them, I did a wrinkle with and when I turned them off I checked again if the code was gone and not then and put back the old MAF sensor and I tried again then it did not start anymore. It cranks but it did not start but the fuel pump, knock sensor, cam sensor, coils spark plugs, and spark plug wire are changed. Yet I have a good fuel pressure 55-60lbs. The injectors work but despite the new coils and everything else it no longer makes a spark and all the fuse and relays have been checked and they are all Okay. Please help me