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I own W212 E350 with a mileage of 92 K .. I do have CEL when i scan the car it throws 0942 and 0946, but I don’t have any signs of a bad catalytic converter.. no strange odor + the car is accelerating good, can it indicate any thing else?
when i do a live data reading the O2 sensor (B1-S1) and (B2-S1) ranges from -0.02 to 0.04 and both (B1-S2/B2-S2) ranges from 0.1 to 0.5 + both catalysts converters temperature ranges from 460 C (if the car is idling - till 650 C if the car just stopped from a trip then it cools down to 460 C … but I notice that the EVAP Purge valve is -527 and climbs till -1000 and the fuel rail pressure is 390 kPa and the LTFT bank 1 and 2 ranges from -7 till +5 depends on the status of the car .. I changed the Fuel filter located behind the drivers seat and the EVAP Sensor but no improvement .. when I disconnected the EVAP sensor it doesn’t throught the catalyst codes
What seems to be the problem
I own W212 E350 with a mileage of 92 K .. I do have CEL when i scan the car it throws 0942 and 0946, but I don’t have any signs of a bad catalytic converter.. no strange odor + the car is accelerating good, can it indicate any thing else?
when i do a live data reading the O2 sensor (B1-S1) and (B2-S1) ranges from -0.02 to 0.04 and both (B1-S2/B2-S2) ranges from 0.1 to 0.5 + both catalysts converters temperature ranges from 460 C (if the car is idling - till 650 C if the car just stopped from a trip then it cools down to 460 C … but I notice that the EVAP Purge valve is -527 and climbs till -1000 and the fuel rail pressure is 390 kPa and the LTFT bank 1 and 2 ranges from -7 till +5 depends on the status of the car .. I changed the Fuel filter located behind the drivers seat and the EVAP Sensor but no improvement .. when I disconnected the EVAP sensor it doesn’t throught the catalyst codes
What seems to be the problem
your fuel rail pressure 60Psi is ok
Does it stay flat or is unstable?
I am asking because LTFT SHOULD NOT swing -7 to +5 !! Should be fixed unchanged
Find why it does... problem will be solved.
your fuel rail pressure 60Psi is ok
Does it stay flat or is unstable?
I am asking because LTFT SHOULD NOT swing -7 to +5 !! Should be fixed unchanged
Find why it does... problem will be solved.
What engine type is this: M272?
Yes it is M272 engine
When the car is idling it’s always between -1.5 to -3
when car is moving it’s around 1 to 7
attached below is the live data after 140 KM
live data collection showing as normal.
LTFT slightly lean.
Does your engine have secondary air injection pump ?? test your air pump mgt valve with your scanner or for air leaking through.
live data collection showing as normal.
LTFT slightly lean.
Does your engine have secondary air injection pump ?? test your air pump mgt valve with your scanner or for air leaking through.
Yes it does have secondary air pump
i think the pump only starts in the first ignition in the morning right?
My Scanner doesn’t have test function, but i do hear the pump turns up in the cold start .. it stays on for almost 30-40 seconds until it gets warm.. should i check the pump’s vacuum hose?
Yes it does have secondary air pump
i think the pump only starts in the first ignition in the morning right?
My Scanner doesn’t have test function, but i do hear the pump turns up in the cold start .. it stays on for almost 30-40 seconds until it gets warm.. should i check the pump’s vacuum hose?
it not so much the pump itself, it's the control valves between pump and the engine. Check if they leak through
So this is M272 engine.
Anyway, your rear oxygen sensors the narrowband ones, the B1-S2 and B2-S2 is reading wrong or very lean if at 0.12 volts and stayed there.
Could be bad sensors, but both at the same time is uncommon, but can happen.
Can your scanner produce Lambda value for the front wideband 02 sensors ?
So front and rear 02 sensors Rich/Lean values compared.
Playing with the throttle from idle to 3,000 RPM should produce rear sensors reading up and down rich/lean, if that does not happen, very high chance your rear 02 sensors are already bad.
The ECM tells you if the CATs are BAD , is from how the rear 02 sensors responding.
Sure you can have BAD CATs, but it/they will not pegged an 02 sensor to 0.12 volts all the time.
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