Catalytic converters have been cut out

2002 MERCURY MOUNTAINEER
160,000 MILES • 4.0L
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LAWRENCE CHENOWETH
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Catalytic converters been cut out, is it okay?
Dec 16, 2019 at 7:52 AM
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AL514
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Hello, you will not get through inspection with a missing converter, the engine computer will see the oxygen sensor reading is false and the check engine light will come on. There is an oxygen sensor In front of and behind the converter to monitor the converters progress in burning off excessive fuel vapors.
Dec 16, 2019 at 8:16 AM
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DANNY L
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Hello, I'm Danny.

It depends in which state you live in ! If you live in California you have to have them. What is the problem otherwise? Is the check engine light on? Is the truck not running well? Let me know and we can figure this out.Hope this helps and thanks for using 2CarPros.
Dec 16, 2019 at 8:17 AM
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LAWRENCE CHENOWETH
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No I live in Indiana, so I'm good. But the truck is not running good.
Dec 16, 2019 at 8:31 AM
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AL514
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That's because the oxygen sensors have been cut out or are just hanging there. The computer reads these sensors while the car is running and is seeing the wrong signals right now causing the air/fuel ratio to be incorrect. It's a major input to the ECM.
Dec 16, 2019 at 9:40 AM
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LAWRENCE CHENOWETH
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No oxygen sensors are there and plugged in.
Dec 16, 2019 at 9:43 AM
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AL514
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I am sure the ECM is reading the exhaust through the oxygen sensors and it's reading a rich signal on the rear oxygen sensor and is compensating for it. The catalytic converter burns off extra fuel which the ECM is expecting to see from the oxygen sensors.
Dec 16, 2019 at 9:47 AM
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LAWRENCE CHENOWETH
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Okay, thank you.
Dec 16, 2019 at 9:48 AM