Galant's Black Smoke & Jerking: Sensor or Bigger Issue?

Had the same symptoms with my '09 Mitsubishi Lancer Diesel last summer. Turned out to be a failing waste gate valve, not the boost sensor. Took it to my regular mechanic when the black smoke and power loss started getting worse. They ran diagnostics and found the waste gate wasn't regulating turbo pressure properly. The valve was stuck partially open, causing inconsistent boost and that nasty black smoke. It was definitely a serious issue that needed immediate attention, running it like that can damage your turbo. The fix involved replacing the entire waste gate assembly. Had to leave the car at the shop for two days, but it sorted out all those symptoms, no more jerking, smoke, or power loss. My Lancer's been running smooth since then. If you're in this situation, don't wait too long to get it checked. These symptoms won't fix themselves and could lead to bigger problems with your turbo system.

Thanks for sharing your experience! That's really helpful since it sounds exactly like what I'm dealing with. My Galant's symptoms match yours perfectly. Do you remember roughly how much the waste gate replacement set you back? Also, curious if you've had any other turbo-related issues pop up since getting it fixed?

Hey there! Happy to help with an update on my Lancer situation. So after seeing the mechanic last month, they actually found that both the boost pressure sensor was faulty AND the waste gate valve needed replacing. The whole thing ended up costing me 860€ for the waste gate work, but it was totally worth it. Since getting it fixed, my car's been running like a dream, no more black smoke, jerking, or any of that drama. Haven't had a single turbo issue since. Actually, the engine feels more responsive than it has in years! Just between us, I probably should've taken it in sooner, but you know how it goes, you keep thinking it'll sort itself out. Big mistake! But yeah, if your Galant's showing the same symptoms, definitely get it checked out. These issues only get worse (and more expensive) if you leave them. Let me know how it goes with yours, always interested to hear if other Mitsubishi owners are dealing with similar stuff!

Just got back from the mechanic and wow, you were spot on! Took it to AutoTech downtown after reading your advice. Turned out my Galant had the same exact issues, faulty waste gate and a shot boost sensor. Bill came to around 900€, which wasn't fun, but the car's running like new now. The whole process took about three days because they had to order some parts, but it was worth the wait. No more black smoke, jerking, or that annoying hissing sound. The idle's smooth as butter now, and the check engine light's finally off. It's amazing how much power I'd actually lost without realizing it! Really appreciate you sharing your experience, it helped me avoid getting the runaround from mechanics who might've just guessed at the problem. Guess I've learned my lesson about waiting too long when these symptoms show up! Thanks again for all the help. Maybe we should start a Mitsubishi owners support group, haha!