Subaru EJ205 Breakdown

Subaru EJ205 Breakdown

Jul 9, '21

The EJ205 was first introduced in 1999 in Japan and 2002 in the US market. The name EJ205 is just a basic designation of an EJ engine, with 2.0 liters of displacement, and the 5 or 7 is an identifier for whether it came out of a WRX/Forester (5) or STi (7).


Swapping some EJ205 engines is much easier than swapping other EJ205s because not all EJ205 engines have the same characteristics. Depending on the year the engine was built it may have AVCS, may be DBW, and it might even be immobilized. It's very important to look at which type of EJ205 before buying so that the most compatible model is purchased for your project.


Not sure which engine you have? What this video to find out!

There are two generations of EJ205s, 1999-2000 and 2001 to current. The biggest difference between the generations in Japan is the 1999-2000 is non AVCS while the 2001 to current generation has AVCS. If an importer lists a JDM EJ205 as non AVCS it is from 1999-2000. We have heard stories of importers labeling these non AVCS engines as 01-04 but this is incorrect, so make sure it has AVCS or know what needs to be done to make it work before purchasing the engine. iWire has more information about AVCS in our other blog post HERE.

Another difference between the generations is that 1999-2000 JDM EJ205's are effectively non OBD2 while the 01+ models are OBD2 equipped. There is also an EJ205 that is Drive by Wire and AVCS equipped which is out of a 2003+ Forester. This is not a good engine to buy because the ECU is immobilized and has no tuning options. Also note that the 2005+ non drive by wire models are immobilized as well, but an older ECU can be put in place to eliminate this issue.

These EJ205s are from 2002-2005. Unlike it's JDM counter part from 2001+, the USDM WRX model does not have AVCS. But don't get this confused with the 1999-2000 models in Japan that are non AVCS because they are very different. The key identifier here is that the JDM models will have a coil pack with spark plug wires unlike the US model that is coil on plug (pics below).

I have a 2002-2005 WRX. What is the best engine choice for a replacement of my current engine?
Generally we would recommend the JDM EJ205 (or 207) from 01-04 because they are a plug and play replacement. Simply add in the AVCS wiring with our AVCS bulkhead wiring kit, plug in the JDM ECU and tune the car (the fuel in Japan is higher quality than here in the US) or just keep the USDM ECU and ignore the AVCS.

NOTE: The USDM WRX ECUs do not have the hardware to control the AVCS. To get this feature to work, you must swap to the JDM ECU.
Another option would be to go with the 1999-2000 engine but it would require swapping over a large number of parts to get it to work but those can be pulled off the original USDM EJ205. Some good info can be found here on how to convert a V5/6 to run in a USDM WRX.

The drive by wire Forester models could also be used, but the intake manifold from the USDM WRX would need to be swapped over. For this instance the iWire Bulkhead AVCS kit as well as the Intake Manifold AVCS kit would be needed.

I have a non turbo model and looking to do a turbo engine swap with an EJ205. Which engine would be a good choice?
For these swaps we would only recommend the JDM EJ205 from 01-04 with AVCS and a mechanical cable throttle or any USDM 02-05 WRX engine. Although the paths listed above for the 2002-2005 WRX could be applied to the older variations of the JDM EJ205, it's generally more work than it's worth. The engines are available so keep the swap simple and get the easiest one to install.

NOTE: The JDM WRX ECUs have been difficult to find. If this is the case, you can utilize a JDM 207 STi ECU as long as you do not have TGVs (STi ECUs don't have the ability to control them open/close) and reflash it for your WRX application.

Unfotunately, iWire does not have any spare ECUs for these applications at this time.

Common EJ205 and EJ207 ECU Sticker Labels:
A7 - 1999 and 2000 WRX - V5/6
F6 - 1999 and 2000 Forester Turbo - V5/6
J2 - 1999 and 2000 STi ECU - V5/6
V7 - 2001 WRX - V7
V8 - 2001 STi - V7
4L - 2002 STi
4M - 2002 WRX - V7
2F - 2002 Forester (cable throttle version)
6L - 2002 STi -V7
5Y - 2003 and 2004 WRX - V8
6A - 2003 and 2004 STi -V8
B1 - 2005 STi (immobilized - do not buy) - V9
F2 - 2005 WRX (immobilized - do not buy) - V9

V2 - 2002 WRX ECU
6G - 2003 WRX ECU
7F - 2004 WRX ECU
6H - 2005 WRX ECU