jenniferjohnson93

GLA Exhaust Leak and NOx Catalyst Problem

My 2022 Mercedes GLA gasoline engine has a recurring problem. The check engine light comes on sometimes, with an error code for NOx storage catalyst aging. I also hear an exhaust leak. My GLA has 97313 km on it. Can an exhaust leak cause the NOx catalyst issue, affecting air quality and fuel efficiency? I used an OBD scanner, and the error code points to the catalyst. I want to understand the connection before I fix anything.

4 comment(s)

A leak in the exhaust system before the NOx catalyst can cause that aging error. The leak adds extra oxygen, messing up the air fuel ratio and possibly hurting the catalyst. Have you looked at the exhaust system for cracks, holes, or loose connections?

I haven't checked under the car yet, but I will. Where are the usual leak spots I should look for, assuming the O2 sensor is okay? Are there weak points on the GLA's exhaust system?

Without seeing the exhaust system, leaks often happen around the exhaust manifold gasket, flex pipes, and exhaust section joints. Given the error code and what's happening, get a workshop to do a smoke test on the exhaust system. It's the best way to find leaks. Ignoring it could hurt fuel efficiency and increase nitrogen oxides emissions.

Thanks for the advice. I took it to a workshop for a smoke test. They found and fixed a leak near the catalytic converter, which seems to have fixed the NOx catalyst issue. The repair was 265€. Thanks for your help.

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