On a clog cat, why would it make the engine run lean?

2001 FORD ESCAPE
50,000 MILES • 6 CYL • 2WD • AUTOMATIC
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MIKELEE7772
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ON a clog cat why would it make the engine on that bank run lean? For all three have miss fire cly, and make that bank run lean?
Dec 22, 2010 at 7:10 AM
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MHPAUTOS
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If anything it will run rich, may be the upstream O2 sensor is causing the ECU to lean it out due to a faulty signal, replace the bad cat and see what you get in the way of codes.

mark (mhpautos)
Dec 28, 2010 at 2:47 AM
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