1999 Infiniti Q45 DIAGNOSTIC TROUBLE CODES

1999 INFINITI Q45
86,900 MILES • V8 • FWD • AUTOMATIC
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RIERIE169
  • MEMBER
  • 1 POST
MY CHECK ENGINE SOON LIGHT CAME ON AND THE SCAN CAME BACK WITH THESE CODES:
PO400, PO158, & PO138. CAN ANYONE TELL ME WHAT THESE CODES MEAN?
Sep 15, 2008 at 6:24 PM
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MHPAUTOS
  • ✓Experienced Mechanic
  • 31,937 POSTS
Hi there,

P0400 is a EGR flow malfunction and the other two are O2 sensor voltage vaults, start with cleaning or replacing the EGR valve the second two codes are responding to the faulty EGR valve.

Mark (mhpautos)
Sep 15, 2008 at 10:04 PM
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