Does anyone know where i can find some cheap high flow cats that have oxygen sensor ports on them? All the one i've found don't have the ports, which means i'll have to buy MIL eliminators. Thanks

 

Are you talking about just the cats or the whole mid-pipe?

The O2 sensors screw into the pipes, not directly to the cats. Any aftermarket mid-pipe should have the holes for the O2 sensors.

 

I thought the factory cats came with sensor holes in them. I want to weld in high flow cats not an entire midpipe, but i need a port for the sensors.

 

It should have O2 sensors just before and then after the cats. They measure the exhaust before entering the cats and after to see if the cats are working properly. If you had a sensor inside the cat it wouldnt work right. I havent looked at a v6 model, but i dont see why it would be any different. Easiest way to tell would be to jack the car up and look for the O2 sensors

 

Ok are both sensors necessary to keep the service light off?

 

Ive never heard of anyone taking the front ones off, so im not sure about them. The rear sensors will cause the light to come on. You only need to worry about the light if you take the cats off. High flow cats shouldnt make your light come on.

If the light does come on there are 2 ways to fix it.
1. Get a tuner and turn the rear sensors off, which is the recommended way to do it.
2. Get mil eliminators. They plug inline with the rear sensors and trick the computer into thinking the sensors are getting the correct signal. Some people say they work, while some people have a lot of trouble with them.

 

pypesexhaust.com look under the muffler section

 

Does the computer change the performance of your engine when hi flow cats are installed, and the flow of unburned fuel is greater between the first o2 sensor and the second one?

 

Do the O2 sensors have a real effect on perforamance at all?

 

Yes, the O2 sensors do affect performance. U want them to basically continue doing their job or get tricked into thinking the exaust conditions are ok.

If you are going to high flow cats the original sensor arrangement should be left intact.

when U remove Cats such as when an off road H or X pipe is used a tuner turns off the REAR sensors or mil eliminators are used. The mil eliminators modify the O2 sensor sygnal so the computer thinks that the sensors reading are ok. This keeps your Check engine light from coming