What should o2 sensors read on live data?
An oxygen sensor will typically generate up to about 0.9 volts when the fuel mixture is rich and there is little unburned oxygen in the exhaust. When the air/fuel mixture is balanced or at the equilibrium point of about 14.7 to 1, the sensor will read around 0.45 volts.
What should my EVAP percentage be?
When EVAP purge is commanded off, the value should be o%, and 100% when it is commanded on. This is an important value o check if the engine has lower than normal LTFT and STFT fuel trim numbers (indicating a rich fuel condition). The purge valve may be leaking vapor into the intake manifold.
What should EGR error be?
If the scan tool displays EGR Error at 99.2% and the EGR is commanded OFF, this indicates that the PCM is receiving information that the EGR valve position is greater than 0%. This may be due to an EGR valve that is stuck partially open or a malfunctioning EGR position sensor.
Is a purge valve normally open or closed?
The Purge Solenoid is normally closed but is opened by the PCM to allow manifold vacuum in the EVAP system — thus drawing fuel vapours from the EVAP system. When the PCM commands the Switching Solenoid to open, the fuel vapours in the tank will be transferred to the canister.
How much vacuum should a purge valve hold?
Squeeze about 7 pounds of vacuum. The vacuum should hold at 7. If it doesn’t hold, replace the valve.
What is an EGR error?
The EGR error is actually the amount of calculated EGR flow error. The PCM determines an expected amount of total mass air flow required for a given engine RPM. The PCM takes this expected value and subtracts the measured intake mass air flow and the remainder is calcultated EGR flow.
What is o2s on code reader?
Code P0134 is triggered when your vehicle’s O2 sensor (bank 1, sensor 1) is malfunctioning. The Engine Control Module (ECM) detects that the Oxygen (O2) sensor is at a standstill and is not accurately reading the amount of oxygen in the exhaust.
Which is the fastest way to interpret generic scan data?
Interpreting Generic Scan Data. In most cases, the fastest possible data rate is approximately 10 times a second with only one parameter selected. If you’re requesting and/or displaying 10 parameters, this slows the data sample rate, and each parameter is reported to the scan tool just once per second.
What is normal operating range of CTS connector?
When the CTS connector is jumped short circuit, the PCM will be reading “0” volts on the wire and display a reading of 389 degrees. Normal operating range for the sensor, when hot, should be 185 to 220 degrees. Voltage will be 3 volts cold .5 volts hot. This sensor has a major influence over fuel mixture when the engine is cold.
What should the downstream HC reading be for a catalytic converter?
For example, if the upstream HC reading is 120 ppm and the downstream HC reading is 12 ppm, the downstream reading is 10% of the upstream reading — which means the converter is working at 90% efficiency. That’s probably good enough to keep emissions within limits.
How is generic scan data interpreted in OBD II?
The PCM receives the data from the oxygen sensor, processes it, then reports it to the scan tool. Also, a fundamental OBD II generic limitation is the speed at which that data is delivered to the scan tool. In most cases, the fastest possible data rate is approximately 10 times a second with only one parameter selected.