Lexus IS DPF Issue

I've got an IS too, and those symptoms sound familiar. Could be backpressure building up. Have you checked for any sensor faults lately? Is your fuel efficiency down?

Sensor faults I haven't checked. And yes, fuel efficiency seems reduced. Could DPF cleaning solve this, or is it likely replacement?

In my case, cleaning didn't do the trick for long. Ultimately, I needed a new filter. I'd recommend getting it checked professionally. I ended up with a 1550€ bill. Don't want to unnecessarily replace it, do you?

Thanks for the insight. Seems a visit to the workshop is unavoidable. They confirmed a defective diesel particulate filter.