Codes only say bad O2 sensors.
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1997 Ford Expedition Question: 5.4 140T miles. It has exhaust leak P's side at a CAT why wont idle?
Answer #1pushrod June 23, 2013, 19:16Master
Fix the obvious stuff first!! Like the exhaust leak, then clear codes, if 02 code comes back replace it. 02 cant read correctly with leak. This just might fix all of your problems.
Replyjohnford, June 23, 2013, 19:54Rookie
Thanks but I failed to mention the O2 faults came first and I was told that they can't make your engine run bad. Can the lack of back-pressure from the leak cause the bad idle?
Replypushrod, June 23, 2013, 20:37Master
You were told wrong! Fix what you know is needed first. Then if it needs more start the diagnosis!