2002 ML320 what is code p0151 and p0432
 

Just pulled the codes for the ML. Can someone tell me how to interpret. Could it be an O2 Sensor?

bump

Anyone?

Here are the explanations for the codes you posted. I would go after the P0151 first then see if the other one goes away once that is fixed.

P0151 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)
Possible causes
- Faulty Front Heated Oxygen Sensor Bank 2
- Front Heated Oxygen Sensor Bank 2 harness is open or shorted
- Front Heated Oxygen Sensor Bank 2 circuit poor electrical connection
- Inappropriate fuel pressure
- Faulty fuel injectors
- Intake air leaks may be faulty
- Exhaust gas leaks

Read more: P0151 Mercedes-Benz O2 Sensor Circuit Low Voltage Bank 2 Sensor 1 OBDII Engine Light Trouble Code | Engine-Codes.com

P0432 Main Catalyst Efficiency Below Threshold (Bank 2)
Potential causes of a P0432 code include: Bad or non-functional catalyst Engine operating out of optimal air:fuel ratio

Read more at: P0432 Main Catalyst Efficiency Below Threshold (Bank 2)
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Great; thanks for the help.

I now have an obvious exhaust leak and it sounds like a hole in the muffler or maybe a gasket between exhaust pipes is leaking. I am guessing that this may be the reason the readings are off and once the exhaust leak is fixed, the other readings may go away. Sound is pretty much up front and somewhere around the front wheels; do not think the leak is anyplace behind the trailing edge of the front tires.

Not sure what it is. Felt for a leak in the mufflers and the crossover pipes but could not feel any air escaping. Really loud; you can hear me coming 50 yards away.