BenzWorld Junior Member
Date registered: Oct 2009
Vehicle: E320 CDI 2005 with 120k miles
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Quoted: 1 Post(s)
Code P0133 Even After Sensors Replacement
Hello, please help.
Got codes P0133 (O2 bank1 sensor1 slow response) and P0140 (sensor2 no activity?). Replaced both sensors with OEM Bosch and cleared codes. Got the same errors. Cleaned MAF just in case, checked electrical connections, and checked for exhaust leaks. Same errors are comming back.
Searched web: code P0140 is not listed in Mercedes startechinfo.com for E420 (although it is on Sticky?!-why?), it is probably a generic OBD. Found info somewhere that 140 follows P0133 so I should concentrate on 133. Also, don't think it is fuel trim because it relates to one bank only(?). FYI: using Actron reader and E420 has 130k miles, spark plugs and air filter are 5k old. Car works fine but I want to clear the CEL.
Additional info: when criss cross wires on left and right sensors got many codes related to malfunctioned sensors and missfire (but no 133) - which means that both sensors are read by the ECM.
My next step is to check the voltage with AC/DC voltmeter - don't have a scope. What voltage should I expect with car in Park?
Any suggestions how to fix this code? Thanks.