Lexus IS diesel CEL power loss smoke

Dude, that sounds eerily familiar! I had almost the exact same symptoms on my IS – check engine light, power loss, and smoke. I'd put money on it being that CCV valve. If it's stuck open, it'll mess with your idle and emissions big time. Have you checked if the hoses connected to the valve are cracked or brittle? That can throw things off too.

Cheers for the fast response! I haven't specifically checked the hoses, but that's next on my list. When you say it messed with your idle, how bad was it? Did it cause any stalling or just rough running?

The idle was rough as guts, jumping all over the place. No stalling, fortunately, but it was definitely noticeable, especially when the engine was cold. Honestly, save yourself the headache and just take it to a decent workshop. They'll diagnose it properly and replace the CCV valve. It's a bit of a fiddly job to get to, plus you want to make sure the replacement part is good quality. If it's the valve, you're probably looking at around 360€ for parts and labor.

Appreciate the insight! Sounds like I'm heading to the workshop. I was hoping it was something simple, but that rough idle you described is spot on. Thanks for confirming my suspicions and the heads up on the repair cost. Will report back once it's sorted.