Subaru WRX and STI (VA, 2015-2021): Reliability mods
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What are the best reliability mods for the Subaru WRX and STI (VA, 2015-2021)?
It depends on the car’s condition and how you use it. These are the 1 reliability build entry we have sourced for this car: Diagnose an FA20DIT before paying for walnut blasting (Limited). Each lists caveats, related problems and sources so you can match it to your goal.
Diagnose an FA20DIT before paying for walnut blasting Limited
On the direct-injected VA WRX, check misfire data, compression and the valves themselves before booking an intake-valve cleaning; one tuning guide says fuel additives do not reach the intake valves on this engine and that deposit severity varies widely.
Caveats: Single source. The same guide also walks through oil level, knock feedback, boost leaks and PCV as separate diagnostic paths.
Related issues: FA20DIT intake valve carbon deposits (direct injection)
Sources (1)
- FA20DIT Common Problems and Reliability: 2015-2021 Subaru WRX — ThinkTuning (tuning guide site, updated August 13, 2026) (editorial; read 2026-10-26; full page read)
More for this car
- All Subaru WRX and STI (VA, 2015-2021) fitment answers · VA common problems
- Newsletter archive: past issues with every new and corrected entry
Report a correction — spotted an error or have a better source? Email hello@chassisdex.com.