Secondary Cat Delete
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Joined: Jan 2025
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w204 c250 cgi mercedes benz
Secondary Cat Delete
I have a 2010 w204 c250 cgi and I was wondering if I remove the secondary cat and straight pipe it will by car have a more lively sound whilst being under 90db. Also will I inhale toxic fumes or fail emisions or have a check engine light if I end up removing the secondary cat?
Super Member
Joined: May 2024
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From: Northern Indiana
2014 c300 w204.080 3.5 v6
You would possibly fail emissions. I don't believe it would throw a code as it only has one O2 sensor back there. Add long as that sensor works and readings are within limits it shouldn't throw a code
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Joined: Aug 2023
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From: MA Coast
W204 2010 C300 4matic Sport M272
The 250 has two? or is it the resonator? I could be wrong but I thought both O2 sensors are installed in the catalytic converter coming off the exhaust manifold. So removing anything after this point should not result in any fault codes popping up.
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Joined: Dec 2023
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From: TN
2013 w204 c250 coupe & 2001 Dodge Ram 2500 24v Cummins
I have a 2010 w204 c250 cgi and I was wondering if I remove the secondary cat and straight pipe it will by car have a more lively sound whilst being under 90db. Also will I inhale toxic fumes or fail emisions or have a check engine light if I end up removing the secondary cat?
there are 2 oxygen sensors located above the catalytic converter as @TimC300 stated. Which is the downpipe on the c250.
as for decibel readings, I cannot confirm actual numbers but it will be significantly louder if you delete the resonator and muffler at the rear of the exhaust.
I don’t think there is a secondary cat. But rather a resonator in the mid pipe.
