Using Fuel Trim to identify type of misfire (can it be done?)
ScannerDanner ScannerDanner
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 Published On Apr 18, 2012

I in this video I am comparing two different cars. A 2000 Lexus RX300 with a wideband O2 sensor and a 2004 Dodge Neon with a narrow band O2 sensor. I created a no fuel misfire and an ignition misfire on both systems. I am NOT teaching wideband/narrow band O2 operation here, just fuel trim reaction to a misfire. Finally, there is another variable to misfire diagnosis using the oxygen sensor and fuel trim and it has to do with the oxygen sensor itself. Does an O2 sensor actually sense oxygen or fuel? Another question to ask yourself is, does unburned fuel in the exhaust affect the oxygen sensor's signal? The answer to this is absolutely yes! You can see it in this video and my explanation of volume of oxygen in the cylinder is incorrect. The reason there was a difference between the no fuel misfire and ignition misfire was because of the fuel leftover in the exhaust.
Here is a video from my premium channel I've titled "the tomato sensor"    • Video  

Engine Performance Diagnostics chapters 4 and 5

Tools used
scan tool

Playlist
(Chapters 4 and 5) Fuel Trim and Oxygen Sensor Testing
   • (Chapters 4 and 5) Fuel Trim and Oxyg...  

Related videos
the "tomato sensor
   • Video  
fuel trim
   • Operation of an oxygen sensor part 2 ...  

For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
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