Trailblazer Diesel Lean Running

Whoa, sounds rough! Lean running on a diesel can be tricky. You mentioned a few good suspects. Have you noticed any changes in fuel economy? And just to be sure, have you checked the basics like the air filter and for any obvious vacuum leaks? Also, have you had the chance to read the OBD2 codes? That could point you to the faulty component, whether it's the oxygen sensor, or something else.

Good call on the OBD2 codes! I probably should have mentioned that. It's throwing a code pointing to an injection valve/injector issue. So, does that pretty much confirm a defective injector then? Is there anything else that could trick the system into thinking it's a fuel issue when it might be something completely different?

An injector code is pretty telling, especially with those symptoms. While it's possible other things could cause a lean condition that might trigger an injector code, it's much more likely the injector itself is the problem, especially at that mileage. Honestly, at this point, I'd recommend taking it to a trusted workshop. They can properly diagnose and replace the injector, saving you time and potential headaches. Messing with the fuel injection system without the right tools and knowledge can be a recipe for disaster!

Thanks a ton! I was hoping it wouldn't come to that, but you're right, fiddling around with injectors sounds like a bad idea for someone like me. I bit the bullet and took it to the shop. Turns out, you nailed it! Defective injector. Cost me 515€ to get it sorted, but at least the Trailblazer is back to its old self. Appreciate the advice!