View Full Version : 96 STS Service Emissions System Service Engine Light

04-28-04, 01:20 PM
Hello all,

I get this sometimes when I full up the tank. I ensure I close the gas cap tightly and i only put 92 Octane in my 96 STS. Is this an 02 Oxygen Sensor problem? The thing is, this usually takes care of itself and the Service engine light turns off after a while. I have replaced the fuel filter, new plugs & Wires, PVC or PCV valve?, new Air filter, New radiator at the dealer, Flushed the tranmission fluid at the dealer, Oil Change, New Tires, Dynomax Turbo Exhaust (I threw in all the work I had done for good measure). The point is, what the %$#%$ is this Service Emissions System error I get occassionally? the only other thing I can think of is the Catalytic Converter (should have its own code) or a O2 sensor. The error doesn't give me a code, so i am stumped right now. The car still runs great, but message is annoying.



04-28-04, 03:05 PM
If the SES light turns on then there is a code set. Has to be. Did you interrogate the onboard diagnostics to see what code was set. The code will be there even if the SES light has gone out...it will be a "history" code.

With the key on, simultaneously press the OFF and WARMER or OFF and PASSENGER WARMER buttons on the climate control panel. Hold the buttons down simultaneously until the onboard diagnostics activates and read off the codes on the DIC.

Trying to guess why the SES light is coming on is pointless. There are hundreds of things that could cause it. Find the code and post back.

04-28-04, 10:11 PM
Thanks, I know how to pull the codes, let me review the history a bit closer and see from there. A code in history may lead me to it.