O2 Sims

[Yont283]

I have a pair of O2 Sims for sale for a 5.3L Silverado. They are used and in perfect condition. They allow you to run with your converters off without setting off any codes. I paid close to 120 for them brand new so make me an offer. Buyer pays shipping, very small box.

 

[Yont283]

NO one wants them?? I will sell them for $80. Price includes shipping.

[elboberino]

I gotta say, I don't know what they do.  Let me know what they do and I'll tell you if I am interested.  Thanks

[MarkD]

You can buy them new for $89 from several places, including Tbyrne (preferred vendor list).

 

Your OBDII vehicle has 4 O2 sensors.  Two in each exhaust track, one before and one after each Catalytic converter.  The 1st O2 in each side of your exhaust is used by your PCM to monitor your air/fuel ratio.  Your PCM uses these values to adjust your timing and fuel injector pulsewidth(how long your injectors allow fuel into each cylinder per camshaft revolution).  

 

The 2nd O2 sensor in each exhaust path is used to make sure your Catalytic converters are doing their job.  The value these O2's send to the PCM must be at least a certain percentage less than the 1st O2 readings or you will get an SES code (error light).  If you unhook them, you will also get a SES code.

 

O2 simms (simulators) provide a signal to your PCM that is lower than what your other O2's will have.  This tells the PCM that your Catalytic converters are working well (even if you have removed them)

[Yont283]

Thanks for explaining Mark.   I bought them when the 99's just came out and they were expensive cause no one made them. I really don't need them so make an offer and I will sell them. Thanks, Chris

[CMNTMXR81]

Also make sure you get the right connectors if you are interested in these, as these O2 simms will work on any GM OBDII setup.  Some O2's are four flat connector and others are a 4 square connector (like pictured).