How to test air and fuel ratio sensor?
Toyota recommends testing a linear air/fuel ratio sensor with the factory scan tool. Fig. 3 (on page 42) shows several captures from the Mastertech scan tool. Using the A/F Control bidirectional test, the fuel mixture was commanded lean, then rich. The last line in the first screen capture shows the mixture being commanded 12% lean.
What causes rough idle after replacing mass air flow sensor?
Replaced air filter and maf sensor. Problems with vehicle turning off seemed to go away but now I have a rough Idle. Car will drop below 1000 rpms and then rev back up to over 1500 like it wants to shut off. Idle problems seem to go away when maf sensor is disconnected. Car throwing codes p0171 and p0102.
Why is my air flow sensor not working?
It is possible that there is a problem with a BARO (barometric pressure) sensor that is reading faulty. Its purpose is to measure atmospheric pressure, the amount of air entering the engine, and supply the ECM with a calculated reading that allows the engine to make corrections accordingly.
What is the problem with the p0102 air conditioner?
The P0102 also leans towards a leak in the intake air system. It is possible that there is a problem with a BARO (barometric pressure) sensor that is reading faulty.
When to replace an air fuel ratio sensor?
If you notice a decrease in fuel efficiency or engine power output, as well as a rough idle, you may have to replace any air-fuel ratio sensors. 1. Decrease in fuel efficiency
How to check and replace an oxygen sensor ( air )?
A P1155 or P1135 code indicates you have a bad sensor. This is common in Toyota and Lexus cars and trucks. Learn how to test the air fuel ratio sensor to see if it is bad, and then learn how to replace the bad sensor. Nice O2 Sensor Socket Kit: http://www.amazon.com/gp/product/B005…
Why did my check engine light come back on after replacing O2 sensor?
Fiance’s dad cleaned out the mass air flow sensor and ran the car a bit more with the old O2 sensors on and the car was running great again, but check engine light came back on with same old codes. I returned the O2 sensor that had the high resistance reading than spec and got a new one, replaced them.
What can cause an O2 sensor to set a different code?
There are also some other possibilities such as an internally leaking EGR system. This will typically set a separate code. A leak in the exhaust system before the (O2) sensor will also cause incorrect readings. The only other possibilities are wiring issues, and computer concerns.