Oxygen sensors keep failing on my 2005 Grand Marquis

Asked by Trains2761 Aug 26, 2019 at 11:38 PM about the 2005 Mercury Grand Marquis LS Premium

Question type: Maintenance & Repair

Check engine came on, code said it was failed upstream O2 sensor (pass side), I install new sensor ,car runs great for 2 days,then idles very rough and check engine comes on again,same code. I've replaced O2 sensor 3 times and each time it fails after about 2 days...What gives?? Please help me figure this weird problem out !!

5 Answers

What is the actual code? Other problems such as running too lean, too rich or vacuum leaks car cause O2 sensor codes to pop up.

3 people found this helpful.

I don't recall the code number,but it was a lean condition. My next step was to actually check for a vacuum leak, but wouldn't that cause a rough idle at all times? The car will idle fine for hours then intermittently go rough, then smooth out, etc.

I suppose it would depend on what is leaking. Start with the PCV and the hose.

1 people found this helpful.
60

Check out fuelpump ,clean with,injectors cleaners,with either chevrontech,additives ,buy at Walmarts,autoparts.store

1 people found this helpful.
60

Check for bad fuel,put fuel treatment,additives,check with auto parts guys.any partstores.hope that helps?

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