There's very little info on forums so you might get surprises. But as far as I know, the engines are mechanically identical.

I think the main difference between markets is additional emissions equipment (TGVs, secondary air pumps, etc.) and jdm cars get a much more aggressive tune. The reason for tuning differences is unknown but speculated to be a combination of better fuel, fewer avg miles driven, more frequent maintenance and lower risk of litigation for blown engines.

 

Definitely hard to find information. I want to accomplish this with no lights

 

Hope this helps. Put a low millage (36,000 mi) JDM in my 2017 that gave up its USDM engine with only 79,000 miles on it. Despite never being driven too hard and always taking care of the oil and changing it regularly she just gave up. Anyway....about 2,000 miles and all is good. Just make sure you use your old wiring harness from your USDM engine and if you want the low oil light to work you will need to use the old oil pan with the hole for the sensor. I had Bill at Broken Motorsports here in NJ. The only thing we really notice is it seems a bit louder than the USDM but we didn't compare them side by side so take that part for what it is worth.

FYI, because of a change in circumstances at work, I have mine listed for sale if anyone is interested, let me know. Thanks

 

So you didn't have to do anything with the cam or the cam sensor? When I contacted the guy who sold me the engine he said the turbo, accessories and intake manifold would all need to be changed.

 

Nope swapped over the wiring harness from the old engine (I don’t not remember about the intake) used JDM turbo and like I said you will need an oil pan with the hole for the sensor if your old one had it. But if you don’t care about that …and it’s not necessary unless you look at that on your triple gauge on the center stack it really doesn’t matter. Mine has been rock solid for close to 2,000 miles with no lights and it runs like a champ. I swear it pulls a little harder but I have nothing but my seat of the pants dyno to back that up.

 

Sorry, yes, used the old intake and wiring harness but everything turbo etc from the JDM

 

Where are you located?

 

Oil pan, wiring harness and intake manifold. That's it? I hope that is the case. You used your USDM ECU correct? Cause they sent me the JDM one as well.

 

You will see the hole for the sensor in the oil pan. Mine is a 17 so it had it where the sensor goes and you have to use your old one if you want that sensor to work. It doesn't effect the engine at all. I think we used my USDM ecu because we didn't have to reprogram it to recognize the key.

 

Oil pan, wiring harness and intake manifold. That's it? I hope that is the case. You used your USDM ECU correct? Cause they sent me the JDM one as well.

The intake is different because of TGVs, so make sure you swap over both TGVs from old engine. Also retain all the emissions stuff from your old engine; KA/KL canister, secondary air pump and EGR.

I think we used my USDM ecu because we didn't have to reprogram it to recognize the key.

USDM ecu has more emissions equipment, JDM ecu might not pass inspection because it technically won't have all the readiness markers. That said no test place looks that close so as long as there are no failed markers it will still pass. Also USDM tune is different and better suited to our fuel and weather variations.

 

FYI, Mine passed emissions with flying colors with the USDM right after the swap was done.

 

Also, I noticed the jdm engine doesn't have an oil cooler/warmer. I see a lot of people would delete these on the EJ's. So I'm guessing that I don't attempt to add it and just zip tie the sensor to a secure location.

 

?? They probably sold it separately. It's just a water cooled sandwich plate that goes under the oil filter. I'd definitely transfer the old one over.

 

Very weird. The S4 made more power so I figured it would have the same or bigger oil cooler. Let us know if you find any other differences.

 

Or you can just use your old oil pan that has the hole for the sensor.

 

It bolts right up …zip tie works fine too if you don’t care about the sensor. The temperature only shows if you have that gauge up on the tripple gauge on the top of the center stack.

 

Yeah, I'm doing the oil pan tonight. You're right, it does look like that's where that last plug-in goes. For some reason I was confusing it with the oil cooling line that I would have to drill and thread to transfer. Thank you for the reminder.

 

I’m doing this same swap on Monday. The engine is out of my customers car and the JDM engine is here Monday morning. I will tell you how it goes.

 

I zip tied it and its fine as long as you don’t want to use the oil temp on your triple meter, there are no issue and no light….about 3,000 miles in and its rock solid and no lights and it pulls hard. My new JDM only had about 36,000 miles and it runs like the car was new.

 

I don't have it plugged in and there is a light but it is running fine. I had to change the wiring harness, the ecu, and the alternator. I don't know if you need to switch the a/c compressor but I did so that I didn't have to mess with refrigerant (pulled mine off to the side during engine swap) changed my intake manifold though I'm not sure it was necessary as the JDM had TGVs as well

 

Do you happen to know if the JDM alternator was causing issues? or did you just swap it before hand? I'm only getting one CEL when trying to crank, and it's the crank position sensor circuit. No CELs for CAM position like everyone else says. Car won't turn over, just cranks infinitely.

 

I had to swap the phasers from the US engine over to the JDM engine in order to eliminate faults for all 4 cam sensors. The reluctor rings ARE DIFFERENT between JDM and USDM. The Japanese ring notches are indented while the US ring notches stick out. I also deleted the oil cooling system below the oil filter and grounded the oil level sswitch wire. Full harness and intake swap.

 

On an FA20?

 

I have a 2020 wrx that blew the motor at roughly 29000 miles. The dealership sold me a lemon and the original owner modded the vehicle that voided the warranty. And I had idea about these mods as they weren’t disclosed to me at the time of purchase. Regardless, I also purchased a JDM fa20. The company that imported the motor told me that I had to swap the intake manifold, cam phasers and exhaust manifold, and a crap ton sensors. The JDM motor has about 24k miles on it. My question is what exactly did you swap to ensure the motor as least runs. I don’t care about the CEL or any other light as I can deal with those later. I have been without a car for about 6 months and desperately need it running. I am planning on going back to the dealership and trading it back in for my mustang. Also WTF IS A CAM PHASER. I am new to the Japanese car scene and just want to go back to good ‘ol American muscle.

 

Cam phaser is for changing valve timing. Vtec by bean counters. All "american muscle" has these now, other than dodge probably. The days of carbs and simple 2 valve engines are long gone.

The CELs are more than lights, they can cause engine damage. The dealership will screw you on your trade-in if there are CELs because they might have to do an engine out to fix everything (if they can) before it will pass inspection.

 

My mustang is a 2 valve. It’s a 2004 GT 4.6L. I understand the CEL’s could mean something bad, however if the light is on for something stupid, like a bad o2 sensor, or if I didn’t tune the car for a passenger to be in the car. I just need this thing running and I’ll solve the CEL or another lights before I trade it back in. I just need a car that runs.

 

I changed the alternator out because the plug was different. If yours isn't im guessing that you didn't change the wiring harness which I was told was mandatory.

 

My mustang is a 2 valve. It’s a 2004 GT 4.6L.

Exactly, that's old enough to graduate college or be in a museum.

I understand the CEL’s could mean something bad, however if the light is on for something stupid, like a bad o2 sensor, or if I didn’t tune the car for a passenger to be in the car. I just need this thing running and I’ll solve the CEL or another lights before I trade it back in. I just need a car that runs.

These engines are extremely sensitive to tuning and sensors. I appreciate the that you want a working car but it will take a lot less time and effort to swap everything while the engine is out of the car instead of chasing faults after the fact.

 

Exactly, that's old enough to graduate college or be in a museum.


These engines are extremely sensitive to tuning and sensors. I appreciate the that you want a working car but it will take a lot less time and effort to swap everything while the engine is out of the car instead of chasing faults after the fact.

I already completed the swap with no CEL’s. I did the swap maybe 3 days after my post. Took my about 15 hours between 2 days

 

I just did this swap on my 2018 wrx and all I did was the cam gears, ocvs, and crankshaft position sensors. I now have p0016,17,18,19 car runs fine or at least it feels fine but I don’t know if I’m missing something and with emissions due in about 3 weeks I’m on a time crunch

 

Any luck on figuring this one out? I have a customer car doing the exact same thing

 

hey i got the cel for the cam position sensor does anybody know how to fix that?

 

Any one still on this thread I’m swapping a USDM WITH A JDM. Curious about what the 1 in sixth digit represents? Can’t seem to find online