The Quick Answer above is the generic definition. What follows is what is documented for the Mercedes-Benz models that log P0432, checked against manufacturer data and owner reports.
DTC/P0432·Mercedes-Benz
P0432 on Mercedes-Benz: Causes, Symptoms and Fix Cost
Quick Answer
Moderate SeveritySafe to drive (short-term)Mercedes-Benz
P0432 on a Mercedes-Benz means the main catalytic converter on Bank 2 has dropped below the efficiency threshold the ECU expects. Bank 2 is the cylinder bank that does not contain cylinder 1, so P0432 only applies to V6, V8, V10, V12, or certain flat engine layouts. It is the Bank 2 equivalent of P0422.
Repair cost on Mercedes-Benz€125 - €1800
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Mercedes-Benz E-Class
2009-2024On W212 and W213 E-Class with M276 V6 or M278 V8 engines, P0432 commonly appears at 180,000 km on the Bank 2 main cat. The M278 V8 (E550 and E63) has very tight underbody packaging on Bank 2, raising the labour estimate. Always check for M276 or M278 balance-shaft and chain wear, since both engine families have known rough-running issues that accelerate cat aging on either bank.
What causes P0432 on a Mercedes-Benz?
Beyond the generic causes listed on the main P0432 page, these are the documented Mercedes-Benz-specific patterns:
Mercedes-Benz E-ClassM276 and M278 balance-shaft wear accelerating cat aging on Bank 2
Mercedes-Benz E-ClassM278 V8 tight underbody packaging on Bank 2 raising labour cost
How to diagnose P0432 on a Mercedes-Benz with OBD2
Follow these steps to pinpoint the root cause of P0432:
- Confirm the engine actually has Bank 2 (V6, V8, V10, V12, or flat layout). On inline engines P0432 indicates a wiring or scan-tool fault
- Read freeze frame data and check for companion codes (P0431, P0430, Bank 2 misfires, Bank 2 lean or rich)
- Inspect the full Bank 2 exhaust run for leaks, particularly at flange joints, slip-fit connectors, and flex pipe sections
- Graph the Bank 2 downstream O2 sensor at steady 2,000 to 2,500 RPM. A healthy main cat keeps it stable around 0.4 to 0.6 V
- Compare Bank 1 vs Bank 2 fuel trims. If Bank 2 long-term fuel trim is consistently 8 percent or more above Bank 1, the underlying mixture imbalance is degrading the Bank 2 cat
How much does P0432 cost to fix on a Mercedes-Benz? (EUR)
Estimated repair costs for P0432 in EUR, compiled across makes. Expect Mercedes-Benz parts and labour towards the upper end of each range.
Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.
Related codes that often appear with P0432 on Mercedes-Benz
These codes commonly cluster with P0432 on Mercedes-Benz vehicles:
Looking for the full P0432 reference (all makes, full diagnosis flow, complete repair cost matrix)?
See the main P0432 guideSkanyx · Mercedes-Benz
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