2005 GMC C1500 oxygen sensor

2005 GMC C1500
190,000 MILES • V8 • 4WD • AUTOMATIC
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JAYEEMT
  • MEMBER
  • 1 POST
i have had my mechanic change o2 sensors, both, and even the wires. after a week, the engine light still comes on, with a dignoistic read of o2 sensors bad. what could be the problem?
Nov 9, 2009 at 10:44 AM
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MHPAUTOS
  • ✓ASE Certified Mechanic
  • 31,937 POSTS
  • ASE Certified Mechanic
Hi there,

Check for a engine vacuum leak, a leaking injector and exhaust leaks up stream of the sensor, start here.

Mark (mhpautos)
Nov 9, 2009 at 5:54 PM
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