Hey guys, one of my Rear O2s is bad. and I went to change both of them this weekend but found it basically impossible to do (one faces up i cant even begin to figure how to get to) the othe is just pretty well stuck there. I was thinking what about justleaving the old ones and plugging in simms instad. much much cheaper than a pair of O2s and very easy to install. what would the problems be with doing this. I would rather change the o2s but $$$ is very tight now and i am chasing a few other bigger problems on the car and am seriously thinking about doing this. Any thoughts on this would be great.

Thanks,

 

Just go with the sims. The only thing is your cat could go bad and you fail emissions but since they don't really do sniffer tests on OBD2 cars you should be fine.

 

Thanks Z95m6,

I think I might do it. Anyone else have any input/experience with this.

Ed

 

hey guys I am new at this so I was wanting to know what the simms do for the car and were can you get them at. I have a 94 Z28 with 130,000 miles on it and nothing has ever been done to it. Trying to work out a few bugs too. My problem is it idles rough in gear. Great website really helps out.
Thanks
Josh

 

Well the SIMS are to fool the computer as to the output of the REAR O2s on OBDII cars. So for key3, sorry you don't have them so you can't benefit from them. The front O2s are for engine control and you don't want to mess with them.

As for ED, well it's hard to say if you will pass or fail for emissions with or without them. They are only used for fooling the PCM into thinking the cats are functioning properly. The O2's in the rear of the cats monitor the efficiency of the cats but only for O2 content of the exhaust gas. If you want a good sim at a great price go here. http://www.o2simulator.com/

My 99 pickup had an exhaust leak. When I took a long trip with trailer in tow, the SES light came on for Cat efficiency. I cleared it several times and it still came up. Finally I gutted the cats and put the sims in from the address above and have been trouble free since May. BUT note that in southern Virginia, they do not do exhaust gas testing or PCM testing either.