2021 Subaru WRX STI Pre-Purchase Inspection Checklist
Known Issues — 2021 Subaru WRX STI
CRITICAL
EJ257 ring land failure under high boost — very common on modified or track cars
CRITICAL
Ring land damage from E85 or aggressive tune without supporting mods
MODERATE
Transmission gear grind — 5th and 6th gear synchro wear
MODERATE
DCCD center differential wear with aggressive use
MODERATE
Oil cooling issues at high ambient temperatures on track
What to Inspect
- Check for engine mods and boosted tune — ring land failure risk increases
- Test all gears for synchronizer grind — especially 5th/6th
- Check compression on all cylinders if modified
- Inspect DCCD differential fluid condition
- Verify oil change history is impeccable
Expected Maintenance Costs
| Service | Interval | Cost |
|---|---|---|
| Oil change (EJ257) | every 3,000-5,000 miles | $60-$100 |
| Transmission fluid | every 20,000 miles | $100-$180 |
| Differential fluid (front/rear/center) | every 20,000 miles | $150-$250 |
| Spark plugs (NGK) | every 30,000 miles | $80-$150 |
| Coolant flush | every 30,000 miles | $100-$160 |
| Brake pads (front) | every 15,000-30,000 miles | $150-$300 |
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