CEL Spark plug non-fouler trick and midpipe questions

MomoP5

Member
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2002 Protege 5
Alright, well now that I know how to get rid of the CEL with the spark plug non-fouler, I have a few questions. Does the non-fouler act as a loophole around sensing something or what because if I bought and installed the catless midpipe from Protegegarage, would I have to purchase an O2 simultor to fake that a cat is actually there or is that what the non-fouler trick does? Also, instead of doing the trick only to the second bung on my obx header, could I do it to both or however many O2 sensors there are just to make sure that there was no possible way for the CEL to come on again? All these sensors and crap and really confusing the crap out of me. If someone could just lay it all down straight that would be most helpful. Thank you.

The setup I want to run is the obx header, to the protegegarage catless midpipe, to the corksport catback system.
 
you need to keep the first O2 sensor on the header, the 2nd one you do the nonfouler setup. the nonfouler makes it so that less exhaust passes by the O2 sensor. that's what that tiny hole in the nonfouler is for.
 
You only need to do it on the second o2. There is no need to change anything on the first one. Have you looked into the resistor/capacitor method? I have an OBX header and MAM midpipe and CEL free for 20k. Costs like $4 and really easy.
 
jflo said:
you need to keep the first O2 sensor on the header, the 2nd one you do the nonfouler setup. the nonfouler makes it so that less exhaust passes by the O2 sensor. that's what that tiny hole in the nonfouler is for.

Ok, thats good to know. What about after installing the catless midpipe though, what do you need to do to fake that there is a cat installed?
 
Pointbreak328 said:
Ok, thats good to know. What about after installing the catless midpipe though, what do you need to do to fake that there is a cat installed?

There are no sensors beyond the 2nd O2 sensor. The only test you'll fail is emissions.
 
I have passed 2 emissions tests with no problems with header & full exhaust using nonfoulers only. Never a CEL either. Also have UDP, no VTCS & SRI. **edit** I do have hi flow magnaflow cat but nothing is hooked up to tailpipe on my emissions test & guy wasn't on ground looking under for the cat either. Basically if no CEL then no problem. My guess is that you could get away with it if no thorough visual under the car.
 
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