Im going to be putting up the custom stainless steal exhaust within the next week. I will be losing the secondary cat so I need some info on the o2 sensor. Ive talked to a lot of people about it one guy said this "You can either buy an O2 simulator, or use some resistors in line with the O2 sensor." I havent heard or seen anything about an 02 simulator for the Protege5, Ive also heard that is a pain in the *** to use the resistors in line with the O2 sensor. Another guy I asked told me this "There are a number of cheap or do-it-yourself O2 simulator boxes out there. I'd check to see which ones are known to work for your car. From what I have seen, some ECUs are more easily fooled than others." Unfortunatly, from my understanding our ECU's arent easily fooled . Phantom has had good success with putting the O2 sensors further apart hopefully that might work, we'll have to see. Any comments? Any known O2 sims. out there?

 

As long as the second O2 comes after the primary cat, I would pretty much guarantee no CEL/MIL would illuminate. Don't make too big of a deal on this. Dump #2 cat and have a blast!

[edit]
BTW this is TurboZX3. Forgot to change users.

 

Thanks! Hopefully it all works out well.

 

Phantom your header replaces the first cat right? and the second cat underneath the shift linkage is still intact? Just a little confused on where these o2 sensors go

here are my questions if you could help me out...

With a header I will lose the first cat and install the o2 sensor that is in the stock manifold on the header itself?

and where is the second o2 sensor, between the two cats or after both? If the second is between the two cats what do you do, mount it after the second cat and fill the original hole or something?

 

You got it.

Between them.

Yup, that's the idea. Give the man a cigar.

 

Thanks dude...

I have been to lazy to get under the car and look around. Acutally, is it true that some of headers for the FS (such as the Autoexe) replace the stock exhaust from the engine head to the second cat. Or do they not quite reach to the second cat? If they did reach you wouldn't even need to worry about filling any mounting holes, just tapping one aft of the cat.