In most cases, a slow response DTC gets fixed with oxygen sensor replacement. What do you do when multiple sensors won’t fix it? Even though the root problem on this Hyundai was human error, the tests and methods I’m showing are still applicable to any vehicle using ‘normal’ zirconia O2 sensors.

Engine Performance Diagnostics chapter 5

symptoms 50

  • check engine light (P0133)

fix 50

  • corrected the swapped O2 sensor connectors

test shown enh 50

  • how to use scan data to evaluate O2 sensor performance, frequency and amplitude
  • how to use scan data/trouble codes while unplugging O2 sensors to identify sensor location
  • understanding how trouble codes can force an open loop condition
  • how to identify closed loop operation based on upstream O2 signal and STFT
  • identifying O2 sensor wires based on sensor-side wire colors
  • causes of an O2 slow response trouble code

Tools used

  • scan tool

end faq

{accordionfaq faqid=accordion15 faqclass="dotluvfaq help2 aligncenter headerbackground headerborder contentbackground contentborder round7" active=item0}


(Chapters 4 and 5) Fuel Trim and Oxygen Sensor Testing

Related videos:

2002 Isuzu Rodeo (misfire, low power case study, reversed O2 connectors):


How to Test a Catalytic Converter (P0420 case study):


Oxygen Sensor Slow Response test (P0134) - Nissan:


O2 sensor testing (fixed lean) P0174, P0154, P0155 - Mitsubishi:


end faq

{accordionfaq faqid=accordion3 faqclass="darkhivefaq defaulticon headerbackground headerborder contentbackground contentborder round5" active=item0}

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

Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium. There is a 14 day free trial.

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!