Bypassing o2 Sensor?

[BsoE30]

Well, 600.00 later on my 325es shes running good, just a loping idle from 800-1500 over and over again. Tested ICV, ICM, TPS, New DME, Vacuum leaks, Rebuilt injectors w/new seals. But, the PO had no o2 sensor on the car so in other words the Ecu/Dme is looking for one thus dumping to much fuel into the system and when Rev'd to limiter dumping black smoke-unburnt fuel i guess? out of the exhaust.

My question is this o2 sensor bypass on ebay will it work and do what i need to do to clear the lopey idle? My father keeps suggesting this is the trick i need to do, but he does not understand the finicky system these cars run on. Will it work? Or will it not? And why?

http://cgi.ebay.com/ebaymotors/OXY-SIM-OBD-II-2-O2-sensor-simulator-Oxygen-Sensor-SIM_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem180340802687QQitemZ180340802687QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories#ebayphotohosting

[BsoE30]

I know it says for obdII cars, but i can splice this right into the o2 sensor wire correct? Or, is there another way around this? Maybe a o2 simulator in other words? Or, better off buying a new o2 sensor? Problem is, o2 sensor is not in stock location because of the po's custom exhaust its half way down the car on the passenger side underneath the backseat.

[DaveSmed]

Nope, that will make your car run like crap. Reason it says for OBDII is because it simulates the rear O2 sensors (post catalyst).

Bite the bullet and fix it right. It will be worth it once its running properly.

[AndrewBird]

Why not just put the stock O2 sensor back in? If you have an aftermarket exhaust with no bung, any muffler shop can weld one in for less then $50. Seems like a no-brainer to me.

[nando]

you don't need an O2 bypass on these cars, our ECUs aren't anywhere near that advanced like an ODBII car either. I wouldn't call it finicky, Motronic 1.0/1.3 is extremely simple realistically.

what you need is a new O2 sensor. sending a fake signal to the computer isn't going to make it run leaner, it needs the EGO feedback to cut back the fuel so it runs properly again.