Wiring harness in good shape? The grounds under the intake intact? I know when I forgot to plug in the coolant temp sensor on the crossover pipe the fans immediately turned on during KO, and throw the coolant temp code.

 

Since the codes always turn on with the key, it will be easy to know when you find your electrical problem. You will only have to turn on the key to see if your repair fixed the problem.

Check any wires or connectors you unplugged or moved during your repairs.

 

It is almost certainly an electrical issue.

P0117, P0118 are cooling system sensor fault codes.
P0128 is a calculated relationship by the computer comparing the coolant sensor output to expected output.
P0327 is a knock sensor fault code.
P0451 has to do with fuel tank pressure.

The first four codes don't even indicate a failing part. Looking for the nexus on these issues leads to the ground system for the car and ECU.

 

You replaced the radiator, thermostat, and (water) pump. @donkpow gave you the code reasons. Check all the wiring, starting at the front, where you replaced those parts. I think the ground strap is near the front. Maybe you strained it or removed it when you replaced the radiator.

 

Thanks for all the suggestions, I will check all the wiring and connections. I will also recheck the grounds, especially the ground by the radiator. I appreciate all the suggestions.

 

Hi, I have a Subaru Forester X Premium 2013. Engine was replaced at 55k miles by oil Consumption recall, I have had some crazy issues hard to diagnose on mine but I still want to keep it. In your case, this might sound nonsense, but by any chance, did you perform any work on the front suspension? Knucle replacement, Axle Sensors?

 

Both front axles two years ago?

 

I had an issue for quite some time related to a defective abs or speed sensor. At 155k miles I decided to work on the whole suspension, struts, bushings, Tie Rods, sway bar Links, ball joints, bearing hubs, etc, everything was replaced. However during that work the mechanic broke the rear left sensor, and replaced with an aftermarket, without telling me. After I got the car back, weeks later the Forester started to behave really strange, randomly. having overheating issues on any of the wheels, vibrations, etc you name it, and only when the weather was really hot (Las Vegas has reached the 122f). No code errors. I looked for issues related to calipers, master cilinder, caliper hoses, brake fluid, ABS module (this is insanely expensive). I started to check all the blogs, videos etc and when I did an in-deep visual inspect, I noticed that one of the sensors looks new, so I asked the mechanic and told me the story, however he insisted that the sensor was a very good OES brand and it was not the issue. So on a very hot day I borrowed a full OBD scanner computer, and after 35 min driving and 105 degrees, that sensor failed. I read on several blogs that aftermarket sensors tend to fail either on high or very low temperature. After that sensor was replaced with a SuBARU OEM (not cheap) the issue was gone.
While looking for a solution I found this youtube video, where an issue with one of the sensors affected the fans, link below.

BTW, for the CV axles, I used 3 different "good" OES brand, and the 3 of them gave me headaches, randomly sudden vibrations, I learnt the hard way that it may be related to the design of the gear (located on the axle) that is used by the sensors to read the speed. It seems Subaru CV axles (at least for this model) have very tight tolerances. I ended buying the OEM axles and again the issue was gone.