5.9l Tapping noise with Video
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Joined: Dec 2023
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The PCM has no real way to tell if the data its getting from the O2's is correct or not. So long as the heater circuits are working, and the PCM sees voltage from the sensor switching hi/lo, it believes everything is good. Trouble is, while it LOOKS like it is working properly, the sensor could be misreading the exhaust, giving bad data to the PCM, and the PCM adjusts injector pulse width according to that bad data. That can give you a rich, or lean condition, (depending on which way it errors) and the engine just won't run right. Easy test is to unplug the front O2 sensor(s), (how many you have depends on year, and federal or cali emissions.) and go for a drive, if it runs better, replace the sensors.
Thanks again
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Joined: Apr 2010
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From: Clayton MI
You want NTK or Denso sensors, they were OEM. As for which ones.... gonna have to crawl under, look, and measure. Have a look at the connectors as well, as there are differences there too. (square vs. round?) Rear O2 sensor only monitors the cat, so, if you aren't getting a code for that one, leave it. (save the money for something else.)