Its a mechanical fix, not exactly sure what it does or how it works. Basically works like the spark plug antifouler trick I assume.

 

ok i emailed ur about this, if anything i will have learned something new.. im just giving advice to this guy that i know works and has worked for many people... hopefully they will respond to me..

 

I agree as above. I have had my UR test pipe for 6 months and 10k miles, CEL came on once then went away next time I turned the car back on. It came on again about 3 months ago and I disc the battery, waited 10 min, re-connected and it was gone, haven't seen it since.

 

pulling the battery justs masks the prob. i bet if you put the car on a diag. check, youll see those thrown codes, and the times you disconnected the battery.. oh and dealers really get aggraveted when they get cars that have these codes. plus they will see you took your cat off...

 

I was told by a vendor for UR (can't remember who) that the way the bung works is that the sensor is taken out of the direct airflow and into that sepearte bung area were it gets much less airflow, similar to the amount of airlfow and o2 it would be subjected to if there was a restrictive cat there. Quite a cool little inventions they have designed!

 

thanks for the info, now after reading that and recieving an email from ur, it semms to be a little better of an idea.. but i would rather have the o2 elim.

 

I have disc my battery only once for the CEL. Besides it is not masking anything. In any case I have disc my battery numerous times for different of things, and not just because of mods. Technically you should disc the battery when working on your car... ex. change sparkk plugs, wires, or install a car stereo. Oh and dealers can kiss my ***.

 

I actually tried to disconect the battery also but the cel went right back on after a couple of hours. The problem is definetly the o2 sensor in the catback was not relocated, can i actually pull the cable out a little bit without breaking or damaging it or sould i cut it and solder ?

 

90% of people know to disconnect the battery when doin work.. but to disconnect the battery to get rid of the check engine light is just that, making the light go away.. it doesnt solve the prob or get rid of the code in the computer.. mitsu can kiss my *** too, but some people on here still need to take there car to the dealer, and need a warrenty, so just disconnecting the battery is not a good practice too have, nor recommended...

 

you deff need to have it in there, try pulling some extra slack out of the body to make it reach, if cut and solder.. also put a little anti-seize on the threads of the o2, as this will make life easier in the long run...

 

90% of people know to disconnect the battery when doin work.. but to disconnect the battery to get rid of the check engine light is just that, making the light go away.. it doesnt solve the prob or get rid of the code in the computer.. mitsu can kiss my *** too, but some people on here still need to take there car to the dealer, and need a warrenty, so just disconnecting the battery is not a good practice too have, nor recommended...
Quote:
Originally Posted by v8killer
I have disc my battery only once for the CEL. Besides it is not masking anything. In any case I have disc my battery numerous times for different of things, and not just because of mods. Technically you should disc the battery when working on your car... ex. change sparkk plugs, wires, or install a car stereo. Oh and dealers can kiss my ***.

 

Hi guys, problem solved ! Did exactly what you said, took the o2 sensor out of the catback and pulled the cables out nice and easy until they reached the testpipe bung. Took out the screw that was in the bung (hard as hell) then put the sensor on and the plug on the catback and covered the remaining cable that was exposed with a little electrical tape just to be on the safe side, no cel whatsoever. Its sad that i paid a "mechanic" to do something that i ended up doing the way it was supposed to.

I think i'll start getting my hands dity again on my evo, at least on things that i can and have the right tools to do the job. Thanks !

 

Almost, but they could have given you a little more explanation. In closed loop the engine cycles between running rich and lean, you can see this if you look at the signal from the front O2 sensor. Going through the cat all sorts of reactions happen where the rich cancels the lean and the rear sensor sees stoichiometric.

WIthout a cat the rear sensor reads just like the front. With a high-flow the reactions aren't complete so the rear sensor tracks the front -- it doesn't read quite as rich or lean, but follows close enough to trigger a CEL.

The mechanical fix does pull the sensor out of the direct flow but "restriction" isn't the key. What it's really doing, by having a small hole to sample the flow, is letting the rich and lean slugs of exhaust mix together and average out. Now the rear sensor reading doesn't vary so much and stays closer to stoich and that keeps the ECU happy.

Dave

 

good explanation! Yeah they didn't go into that much detail when they explained it to me... probably because I had already bought the test-pipe!

 

Since I'm dealing with all kinds of problems with the CEL light, p0139 code to be precise since I don't have the cat, how much of a difference there is if you move the 02 sensor from the cat to the test pipe??