Lexus LFA Exhaust Leak Rough Running

My 2012 Lexus LFA with a gasoline engine has a check engine light and runs rough. I smell exhaust and think there's a leak. The car has 129652 km. Could this be the catalytic converter or particulate filter?

4 comment(s)

Check engine light, rough running, exhaust leak, and smell points to a defective lambda sensor. Has the exhaust system had any recent work? Any change in fuel consumption? A faulty oxygen sensor affects the catalytic converter, but we need more data.

No recent exhaust work. Fuel consumption seems normal. Could a bad lambda sensor cause an exhaust leak, or are these separate issues?

A lambda sensor monitors exhaust gases, but a severe malfunction could cause combustion inefficiencies, increasing back pressure and worsening a weak spot in the exhaust system. The exhaust leak is probably separate, maybe a crack or failing gasket. Get a professional diagnosis to pinpoint the source before replacing parts.

I took it to a shop, and they confirmed a defective lambda sensor and a small crack in the exhaust manifold gasket causing the leak. The total repair was 375€ for parts and labor. Thanks for the help.

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