I've got a custom exhuast on my 97 and tore out the cat. I've got the check engine light on, but the 3.9 definatley seems to be running too rich. Are there any oxygen sensor simulators that do not require actually screwing in the sensor cause I didn't put a hole in my pipe for it and dont feel like doing it unless i have too. Thanks

 

Not that Ive seen or heard of... buy a new cat and put back in your O2 sensors...proaly would be cheaper than all the gas...

 

mine doesnt actually screw in but you have to wire it into the wires on your preexisting o2 sensor. the heating element cant be by passed on your o2. however your secondary o2 sensor has nothing to do with running rich. it just tells your computer if your cat is bad or not

 

I got mine from Jeg's, and it just plugs into the harness side pigtail. So you wouldn't have to put a hole in your pipe with that one.

 

Does the OSS improve performance? I've been curious, and I've heard that it does, butI haven't heard enough to make an educated decision,and I know Fastman.com sells it.

 

Can't say for sure, I didn't really notice anything. I wouldn't think so cause as mentioned it basicallyjust tells the computer the cat is good and eliminates the cel. Getting rid of the cat or going to a hi-flow one might help performance, but I don't think the OSS alone will.

 

It will do nothing for performance. It will simply get rid of the check engine light associated with a bad cat.

 

If you're putting a simulator in for the pre-cat O2, you're going to mess up your A/F ratio since that one tells the ECU if it's running rich or lean. The after-cat O2 only tells the ECU if the cat is running properly.

 

my high outputconverter keeps making my oxygen sensor throw a code more and more constantly now. If I get a simulator, will I only need one for the post converter?

 

i took the cat off mine and the engine lite come on too i bought a special pipe that angles the sensor pointing twords the back of the truck adn the sensor is sunken back a lil bit and the check engine lite is off now i think as long as the sensor isnt in the line of the exhaust it should be fine mine has 175,000 on it soo i need it tuned(burns rich too)