What exactly do O2 sims do? Do they trick the computer into getting to same readings all the time no matter what? I have JBA Headers and Magnaflow muffler and was thinking about getting cutouts. Don't I need O2 simulators for this?

How about when I want to be legal with the cutouts closed allowing the exhaust to go through my cats and muffler? I don't need factory O2 sensors? My sims will be OK?

Please explain. Any help will be appreciated.

 

To answer your question about sims...they send a fake message to the comp telling it that the exhaust is running within factory parameters thus not throwing a code which allows you to do whatever you want with your system. No you shouldnt need o2 sims for your headers and cat back. (im pretty sure) If you do get the cutouts you will need to have on o2 sims if you put the cutout before the o2 sensors. (Right after the headers before the cats, o2 sims are on before the cats im pretty sure and one on the y-
pipe) my 2 cents

 

You have 2 pairs of O2 sensors. The 2 before the cats read the oxygen content and adjust the computer fuel injection. The ones after the catalytic converters just monitor the efficiency of the cats. If you remove the cats, you need the O2 sims to fool the computer into thinking the converters are functioning properly. They don't change the way the truck runs at all, they just keep the SES light on the dash from coming on.

<small>[ April 19, 2003, 09:25 AM: Message edited by: BigTex ]</small>

 

Even if you have the cutout closed, you can leave the 02 sims plugged in. They will be fine and your truck will run normal.

 

thanks guys