Rough Idle and Exhaust Fumes

Hi, I'm having a real headache with my 2001 Peugeot 406 (gasoline engine). The check engine light keeps popping on, and the engine runs really rough, especially at idle. Plus, I swear I can smell exhaust fumes more strongly than usual, and I think I might even have a small leak somewhere in the system. Any ideas what might be causing this? Mileage is at 64767 km.

4 comment(s)

Sounds familiar! I had similar symptoms with my 406. Have you checked the lambda sensor? Mine was faulty and causing all sorts of havoc with the exhaust and engine performance.

The lambda sensor, huh? Where is that exactly, and is it something I could check myself, or am I better off taking it to a mechanic?

Yeah, the lambda sensor, or oxygen sensor, sits in the exhaust pipe. Honestly, unless you're comfortable working on cars, I'd suggest getting it checked by a professional. Could be a pain to get to, and you'll need the right tools. Plus, if it IS the sensor, you'll likely need a diagnostic tool to clear the error code after replacing it.

Thanks a bunch for the advice! I took it to a local garage, and you were spot on – faulty lambda sensor! They replaced it, cleared the error code, and now it's running smoothly again. Cost me around 375€, but it was worth it. Really appreciate the help!

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