Santro Exhaust Treatment Malfunction

Whoa, that sounds familiar! I have a Santro too, and I had nearly the same symptoms a while back. Engine light on, rough running, and that awful exhaust smell...yep, sounds like my nightmare. Was it the oxygen sensor, or something nastier involving the catalytic converter? Did you try reading the error codes, or are you just guessing about the lambda sensor?

The error codes point towards the lambda sensor. However, could a faulty catalytic converter mimic these symptoms? I'm trying to find the most economical solution. Replacing the lambda sensor seems easier than tackling the entire exhaust system, no?

Okay, lambda sensor error codes definitely point in that direction! In my case, replacing the sensor didn't fully resolve the issue. The rough running persisted until the workshop diagnosed a clogged catalytic converter caused by the faulty sensor. So, while the sensor is likely the primary problem, be prepared for potential downstream effects. Honestly, just take it to a reliable workshop; it will save you money and time. Don't risk damaging the engine or particulate filter even more!

I've taken your advice and sought professional assistance. The diagnosis confirmed a defective lambda sensor, as suspected. The repair, including parts and labor, amounted to 375€. I am very grateful for your help!