02 Sensor Fail Code-sensor Didnt Fix??

[tonyvt328is]

i HAVE AN 02 SENSOR FAIL CODE-SENSOR DIDNT FIX??

Short-long story. Shop removed exhaust to replace drive shaft.--ok vibration fixed.

heated manifolds to remove broken studs... welded parts of exhaust back together.

code now shows both front 02 sensors bad. Bought 2 had him replace one..

Still have the same code??? They have no clue.. I hate to go to the stealer..

I need help im loosing my mind.. and $$$$$$$$$$$$$$$$$$$$

Anyone ???

[bill g]

Check the wiring and connections to the sensors - if they are damaged or not making proper contact the control unit will not get the proper feedback from the sensors - resulting in fault code.

Bill G

[winfred]

the most common cause of false 02 codes on any obdII bmw is intake leaks though the cyclonic valve (pcv system) start the engine cold and spray all around and under the intake manifold with carb cleaner, if the idle changes you have a leak, you can try it hot too, another cause is a dead cam sensor but that usually throws it's own code

ps if you only changed one front (pre cat) sensor change the other, only doing one can piss the system off as the new sensor will react much faster then the old one

[tonyvt328is]

the most common cause of false 02 codes on any obdII bmw is intake leaks though the cyclonic valve (pcv system) start the engine cold and spray all around and under the intake manifold with carb cleaner, if the idle changes you have a leak, you can try it hot too, another cause is a dead cam sensor but that usually throws it's own code

ps if you only changed one front (pre cat) sensor change the other, only doing one can piss the system off as the new sensor will react much faster then the old one

Thanks for your input guys! I still need help!!

The shop that did it said they checked over and over and cant find it. (wires) He did replace one and it is still throwing the code. Can a leak throw the 02 sensor code? the story is he removed the exhaust to do the drive shaft. Heated manifold to remove broken studs. (says he does it all the time) not..BMW.. welded some of the exhaust parts back. (didnt remove the battery cable) again says he does it all the time with just the welding ground cable.

Im no dummy I think I am going to double check everything my self .. But I dont have any code reader. Thanks and keep posting your ideas if you will!

[JJ Lochman]

check this place I think i read a post on something like what your asking.... i dont remember where but just try a search, sorry man JJ http://www.unitedbimmer.com/