2001 Monte Carlo Running Rich

Tiny
NCLARK
  • MEMBER
  • 2001 CHEVROLET MONTE CARLO
I have a 2001 Monte Carlo LS with about 117,000 miles on it. After the infamous coolant/oil leak, I repaired the intake manifold gaskets. In the process, I also replaced both O2 sensors and the catalytic converter, as well as the throttle body gasket.

That being said, I am still getting error code P0420. I have noticed that my car is running VERY rich - half a talk of gas gets the car about 100 miles. There are no leaks (no fluid under the car) and no noticeable out of place smells.

Why is my car running so rich, and how can I make it return to normal?
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Thursday, November 8th, 2007 AT 10:27 PM

3 Replies

Tiny
BLACKOP555
  • EXPERT
That code has to do with the catalyst system.

An oxygen sensor is not functioning properly
The engine coolant temperature sensor is not working properly
Damaged exhaust manifold / catalytic converter / exhaust pipe
or bad ignition timing.
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Friday, November 9th, 2007 AT 6:40 AM
Tiny
NCLARK
  • MEMBER
The coolant temp sensor apparently died before/during the gasket replacement. The $15 part fixed it right up.
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Saturday, November 10th, 2007 AT 12:12 PM
Tiny
BLACKOP555
  • EXPERT
Your most welcome :P
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Saturday, November 10th, 2007 AT 1:32 PM

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