P0175 on the 2022 Mercedes-Benz E-Class (W213)
A P0175 code on your 2022 Mercedes-Benz E-Class means bank 2 is running richer than the ECU can correct. The 2022 W213 E-Class offered the M264 2.0-liter turbo four-cylinder (255 hp in the E 350) or the M256 3.0-liter turbo inline-six (362 hp in the E 450). Both engines feature 48-volt mild hybrid technology with an integrated starter-generator. Bank 2 refers to the rear cylinder group on both engines. At two to four years old, most 2022 E-Class vehicles should still be under the Mercedes-Benz 4-year/50,000-mile warranty.
Symptoms
- Yellow check engine light
- Reduced fuel economy
- Black or dark exhaust smoke
- Rough idle, below E-Class refinement standards
- Fuel smell from exhaust
- Possible power reduction
W213 E-Class Engine Options
The M264 four-cylinder is a capable engine with EQ Boost mild hybrid assist, direct injection, and variable valve timing. The M256 inline-six is a more powerful, smoother option with the same mild hybrid technology plus an electric supercharger for immediate boost response. Both engines are technically sophisticated and require dealer-level diagnostics for proper P0175 investigation. The M256 is considered one of the finest engines Mercedes has produced in recent years.
Ranked Causes
1. Bank 2 Lambda Sensor Issue
The wideband lambda sensor on bank 2 can degrade after two to four years of service. Mercedes lambda sensors operate in extreme exhaust temperatures and can develop measurement drift or slow response times. The ECU relies on accurate sensor data for lambda control, and any inaccuracy causes over-fueling on the affected bank.
2. High-Pressure Fuel Injector Problem
Mercedes direct injection operates at pressures up to 350 bar. An injector on bank 2 that develops a seal issue, spray pattern defect, or electrical fault adds improperly metered fuel. At this age, manufacturing defects are more likely than wear-related failure, though early-onset carbon deposits can affect injector performance.
3. EQ Boost or Turbo System Fault
The 48-volt EQ Boost system (M264) or electric supercharger (M256) provides electric boost to supplement the exhaust turbocharger. If the electric boost component malfunctions, the transition between electric and exhaust turbo boost becomes inconsistent, creating conditions where the fuel map does not match actual air charge.
4. Variable Valve Timing Fault
Both engines use variable valve timing with hydraulic actuators controlled by the ECU. A timing actuator issue on bank 2 alters cam positioning, affecting cylinder filling and exhaust gas composition. This changes combustion behavior enough to push fuel trims past the P0175 threshold.
Diagnostic Steps
- Use Mercedes XENTRY diagnostics to read all faults with freeze frame and adaptation data
- Review lambda sensor adaptation values and aging data for bank 2
- Monitor fuel trims at idle, cruise, and under boost conditions
- Check EQ Boost system operation and electric supercharger function (M256)
- Evaluate variable valve timing actuator positions and adaptation values
- Test fuel rail pressure under various operating conditions
- Inspect intake system for leaks
Costs and Warranty
Under warranty: $0. Out of pocket at Mercedes dealer: Lambda sensor $350 to $700. Fuel injector $450 to $1,100. EQ Boost/turbo repair $500 to $1,500. Valve timing repair $400 to $900. Mercedes dealer labor: $170 to $240/hour. Independent specialist: $110 to $170/hour. Check warranty eligibility before any out-of-pocket spending.
E-Class Ownership Value
The E-Class is a significant investment, and maintaining proper engine function protects that value. A clean service record with prompt attention to check engine lights demonstrates responsible ownership and supports resale value. Fix P0175 under warranty to keep your E-Class in top condition.