If you're shopping for a used Subaru WRX or STI, it could be one of the best decisions you ever make. Or it could turn into a very expensive lesson.
We work on these cars every single day. We build them, tune them, inspect them, and sometimes unfortunately replace engines in them. So we want to walk you through what actually matters when buying a used WRX or STI, whether it is bone stock or heavily modified. This is not meant to scare you away from the platform. A properly maintained WRX or STI is an absolute blast to own. You just need to go into it with the right information.
The Biggest Concern: Engine Failure
Let’s start with what everyone worries about, engine replacements. The most common failures we see on older EJ-based cars include:
- Spun rod bearings
- Cracked ringlands
- Oil starvation
- Poor tuning
Most of the time, it comes down to small mistakes during ownership:
- Running too thin of oil
- Letting oil levels drop
- Not tuning properly for installed parts
- Using an off-the-shelf map that does not match the hardware
It is rarely just random failure. It is usually maintenance or tuning related. Here is something important to understand, just because a car is modified does not mean it is a bad purchase. Just because a car is stock does not mean it is safe. We see failures across the board.
EJ vs FA Engines: Know What You Are Buying
If you are looking at:
- 2004 to 2014 WRX models, you are dealing with the EJ engine
- 2015 and newer WRX models, you are looking at the FA engine
- 2004 to 2021 STI models stayed with the EJ engine
The EJ platform has been around for decades. It is well understood and responds very well to proper tuning and maintenance. It also demands attention to oiling and calibration. The FA platform has different characteristics and maintenance considerations. If you are shopping 2015 and newer WRXs, make sure you understand those differences. Research the specific chassis and engine you are buying.
WRX vs STI: What Is the Difference in Ownership?
The STI typically holds value better and comes with stronger drivetrain components from the factory. It is more desirable on the resale market. Because of that, they are usually priced higher. They are also often driven harder. WRXs are generally more affordable. That can mean an easier entry point into the platform. It can also mean a wider range of ownership histories. The condition of the car matters more than the badge on the trunk. If you are wondering if they drive different, the answer is, yes. You can really tell the STI has a more rigid and tough transmission when shifting gears. The WRX will feel slightly cheaper but still smooth.
What to Look for During Inspection
*Do not just pop the hood and call it good.*
Paint and Body
- Check for mismatched paint between panels
- Look closely at bumpers since they are often replaced
- Inspect panel gaps and alignment
- Look for signs of previous collision repair
These cars are getting older. It is common for them to have had some paint work done. You just want it done correctly.
Rust Areas to Watch
- Rocker panels
- Pinch welds
- Under side skirts
- Over-fender mounting points
- Spare tire well
Pinch welds are frequently bent from improper jacking. That alone is not catastrophic, but it tells you how the car was handled. Rust in structural areas can become a much bigger repair.
Modified Cars Are Not Automatically Bad
Most used WRXs and STIs will have some level of modification, that is normal, what matters is how it was done.
Look at the Install Quality
- Is hose routing clean?
- Are there oil or coolant leaks?
- Does anything look rushed or hacked together?
- Are there exhaust leaks?
A clean install usually reflects careful ownership.
Pay Attention to Parts
Well-known brands that are proven on the platform are usually a good sign. If someone invested in quality parts, there is a better chance they cared about the build.
Supporting Mods We Like to See
On EJ cars especially, preventative oiling upgrades matter.
- Air oil separators
- Upgraded oil pickup and baffle
Oil starvation is a known issue on the EJ platform. Seeing these upgrades is a positive sign.
The Most Important Test Before You Buy
If you do one thing before buying a used WRX or STI, do this. Get a compression test and a leak down test.
These tests tell you:
- Cylinder health
- Early ringland issues
- Overall engine condition
If the seller cannot provide numbers, arrange a pre-purchase inspection at a reputable performance shop. It is far better to spend a few hundred dollars on inspection than thousands on an engine.
Tuning Matters More Than Anything
These cars rely heavily on proper tuning.
Things to verify:
- Who tuned the car
- Whether there is documentation
- Whether the installed parts match the tune
- Whether it was custom tuned for the hardware
There are no safe shortcuts here. A proper tune calibrated specifically for the parts on the car is critical for long-term reliability. A Subaru can have all the right parts and still fail if the calibration is wrong.
Transmission and Clutch Checks
On Subaru STI models especially:
- Excessive shifter movement in gear can indicate worn bushings
- A clutch that engages very high in the pedal travel may need replacement soon
Neither of these are deal breakers, but they should factor into your budget and negotiation.
Is the WRX or STI Worth It?
A well maintained WRX or STI is one of the most engaging AWD performance platforms you can own. They respond incredibly well to thoughtful modifications and proper maintenance. We have seen customers enjoy years of reliable ownership. We have also seen customers skip inspections and face five-figure repair bills within weeks. The difference is preparation.
Get a Pre-Purchase Inspection
Before committing to a used WRX or STI:
- Get compression and leakdown numbers
- Put it on a lift
- Check thoroughly for leaks and rust
- Listen for bearing or valvetrain noise
As a shop, we would rather tell you to walk away than see you buy something that needs major repairs shortly after purchase. If you are local to us, we perform pre-purchase inspections regularly and are happy to help you make an informed decision.
Final Thoughts
Buying a used WRX or STI can be an incredible experience. It can also be expensive if you rush into it without proper checks. Do your homework. Verify the tune. Inspect the chassis. Check compression. Ask for documentation. If everything checks out, you are stepping into one of the most rewarding AWD performance platforms out there. And when it is done right, it is absolutely worth it.
