Previa rough running exhaust smell

I had something similar happen on my Previa, though mine is a bit older. Rough running and exhaust smell sounds familiar. Have you checked your NOx sensors or EGR valve lately? Could be related to those as well. Is the exhaust actually leaking—can you see or feel it?

I haven't specifically checked the NOx sensors or EGR valve yet. I did a quick visual inspection of the exhaust pipe and could see some soot around one of the joints, so there might indeed be a leak. Did you end up fixing the exhaust leak, or was it just the sensors in your case?

Mine ended up being a defective oxygen sensor, causing the exhaust treatment to malfunction and create a leak. The soot around the joint sounds like you definitely have a physical leak too. Probably best to get it up on a lift and have a proper look, maybe even at a workshop.

Sounds like a trip to the workshop is in order. I'll get it checked out, especially those exhaust leak. I replaced the lambda sensor and had the exhaust patched, and it cost around 375€. Hopefully, it sorts things out.