2000 Saturn SL2 Failed emissions

MISSY815

MEMBER
2000 SATURN SL2
4 CYL
4WD
AUTOMATIC
115,988 MILES

Service engine soon light came on approximately week prior to inspection. Failed inspection due to emissions. I then took car to Pep Boys for check light diagnostics. Results came back indicating code P0133. They were unable to work on becuase not certified by DMV. Could this code be the reason for the SES light and/or emissions failure? From your past experiences, does replacing oxygen sensor resolve this issue? Any help you may be qble to provide would be most appreciative.

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

It goes both ways -If the light don't come on and light comes on while engine running you flunk

The computer has identified a problem with the oxygen sensor

The O2 sensor reads unburned oxygen in the exhaust, and generates a voltage signal that is proportional to the amount of oxygen in the exhaust. The signal can vary from a low of about 0.1 volts up to a high of about 0.9 volts. A low voltage signal indicates a lean fuel mixture. A high voltage signal indicates a rich fuel mixture. The engine computer uses the O2 sensor's input to balance the fuel mixture during closed loop operation. A bad sensor may prevent the system from going into closed loop, and usually causes the fuel mixture to run rich causing an increase in fuel consumption and emissions.

A low voltage (lean) reading may indicate a bad O2 sensor, a vacuum leak, or a condition that allows unburned oxygen to enter the exhaust. Check intake vacuum at idle, and inspect vacuum hose connections. If okay, check for a misfiring cylinder, a burned exhaust valve that is leaking compression, or a leaky exhaust manifold gasket.