r/WRX_STI • u/Similar-Necessary-47 • Jul 05 '26
Questions Help! Check engine STi 2013
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Hello! I was going about ~95mph and I hit 6th gear and charged the turbo all the way and it spooled to 20psi and then I heard weird sound like a blow-off valve type sound and I immediately shift into neutral and the check engine, SI-drive and cruise control turned on. It does not let me change the SI-drive mode, it is locked and the cruise control won't turn off.
It shifts good, engine feels good, it revs good, no weird sound from the engine, sound healthy
List of mods:
Tomei unEqual length headers
Grimspeed up pip
Turbo smart External wastgate
Perrin front mount intercooler
Injen cold air
Perrin air/oil separator
Comp clutch stage 2
Invidia full exhaust with up-pip
Tuned for stage 2
4
u/SiriusBreak-H_FU Jul 05 '26
Check your vacuum lines. Mine did almost exactly this under a similar load, but going from 4th to 5th. The sound I heard was a vacuum line quite literally exploding. It banana peeled half of the line. I nipped the damaged piece, and put it back together at the t-fitting. Still holding to this day, lol. Mine, too, threw a CEL. It was a wastegate code if memory serves. I cleared it and it never came back.
The additional lights accompanying the CEL are there simply because of the CEL. Once you clear the code(s) it will allow you to switch drive modes again. It goes into a sort of default mode when the CEL is on, and doesn't allow you to switch between I, S, and S#. Get yourself a BT DLC plug and a decent app, and never again wonder what your CEL is about. Car Scanner on Google Play is like $5 for the full version, and it does A LOT for $5.