Mercury Marquis P Codes (Powertrain) P0400 - P0499

Browse Mercury Marquis P Codes (Powertrain) P0400 - P0499 questions and answers. Choose a question that matches your symptoms.

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2001 Mercury Marquis Engine Code For Possible Bad Cat...

2001 MERCURY MARQUIS

The Check Engine Light Is On, My Scanner Shows A Code Of P0430 Which Indicates A Possible Bad Catalytic Converter Or A Bad O2 Sensor. Don't...

1 ANSWER

Asked by hydroguy

2000 MERCURY MARQUIS

Just Bought This Car That Has Not Been Driven For About Two Years. I Completely Ran The Car On That Two Year Old Gas Before I Refueled. ...

1 ANSWER

Asked by brtfc

2000 MERCURY MARQUIS

It Started As Codes P0305,p0307. Misfires On Cylinders 5 And 7. I Purchased New Coil Packs For The Two Cylinders And New Plugs For All 8 And...

1 ANSWER

Asked by roughouthere

2000 MERCURY MARQUIS

I Recently Had The Po 420 Code Show Up On My Grand Marquis. I've Replaced The Downstream O2 Sensor On Bank One. It Didn't Fix The Problem...

1 ANSWER

Asked by gnorton52

1998 MERCURY MARQUIS

Code P0430 Keeps Engine Light On All The Time. Have Been Told By Others It Is A Bad Ox Sensor And Won't Do Any Harm. Is This True? And...

1 ANSWER

Asked by Eric M

1997 MERCURY MARQUIS

Catalyst System Efficiency Below Threshold Bank 1 Is What Shows Up. Took It In Auto Zone Did A Diagnostic And Showed Cadalack Coverter. But...

1 ANSWER

Asked by debbie taufi

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