Mercedes ML diesel exhaust back pressure sensor issue

Oh my stars, that sounds awful! A smoky diesel is never a good sign. It's like when your oven is on self-clean and you accidentally open it – just a cloud of wrongness! Now, I'm no expert, but could it be something else causing the sensor to throw a code? Have you checked for any leaks in the exhaust system itself? Maybe a cracked pipe could mess with the pressure readings? Just thinking out loud here, because sensors can be finicky things.

Leaks, huh? Good point. I haven't visually inspected the exhaust system for cracks. Where exactly should I be looking? Is there a specific area that's prone to leaks on these MLs?

While I admire your willingness to get down and dirty, poking around a hot exhaust system is like trying to defuse a bomb with a spoon – potentially messy and probably ineffective! Honestly, with those symptoms pointing so strongly to the pressure sensor and the DPF not regenerating, it really does sound like the sensor is the prime suspect. My advice? Get it hooked up to vehicle diagnostics at a workshop. They can confirm the sensor is faulty before you start replacing parts.

Thanks. That's what I suspected. I had a friend run vehicle diagnostics and the pressure sensor error came up. Bit the bullet and replaced it. Total cost was around 245€. The warning light is gone, no more smoke, and it seems to be regenerating properly again.