I am going to change my drivers side cat converter, i plan to change my o2 sensors too, after placing an order for 2 bosch 4 wire sensors, i found out the sensors were not specified if they are for the drivers side or passengers side nor pre or post converter. Am i going to face problems if the pre or post are interchange between the left and right side? please kindly share your opinion.

 

Kimi, long time no speak... Anyways, if you ordered the bosch universal 4 wire o2 sensors, then they should work for both front and rear positions. Factory default ones have brown connector for the left rear, green connector for the right rear and black for both of the front one. If you are using the universal ones, just make sure to cut the wire and keep the length of the wires pretty much the same with the factory sensors.

 

how do you Hxgaser, and thanx for the warm well come back, feels good to be back on the forum and as always you can be counted on for reliable answers. thank you. its been a long day with my converter. i felt like an OBGYN delivering a baby turning and pushing to replace the new converter. i feel beaten up. much worst than the timing belt job for some reason. tomorrow i will complete with the mounting of the 02 sensors while bearing in mind your advice. im going to change only the post conv. both sides, what do you say?

 

Which year A6 and which engine and transmission? Also, be sure to use anti-seize compound on all exhaust bolts and nuts. New oxygen sensors usually already have this on them. I have replaced many exhaust bolts, nuts and studs with stainless steel.

 

Are you getting any codes? Typically (but not always) the codes are usually related to the front ones.

 

yes i got 2 codes. p0421 bank 1 and p0159. i got a massive leakage at the exhaust clamp after reusing the old one, i am wondering if the code P0159 is associated with this. i intend to replace it though. thanks guys

 

can some one tell me were is located the temperature control switch?

 

P0421 is bank 1 pre converter related. If it comes back after the catalytic converter replacement, then it is either the front o2 sensor or the ecu upgrade issue.

P0159 is the bank 2 rear converter related. Large exhaust leak may cause that code to pop up. Replace the clamp and see what happens.

What do you mean by the temperature control switch? Heater control switch? Engine coolant temperature sensor?

 

i did change left side cat.con. and both side post cat 02 sensors. at this point i just cant pin point if this code reflects malfunctioning right side cat or the pre cat 02 . I did order the clamp though to be replaced monday, hoping to eliminate the P0159. what is this story about ECU upgrade? i did read about it some time ago but after talking to audi, they claim there is no ECU upgrade for catalytic converters, could you shed more light on this? i will keep you updated

 

concerning the temp control switch, i found where it is located. My friend's A/C comes on but would not cool the car, at first i thought of the temp switch which after replacing has failed to provide results. after examining the vent operators, i noticed the climate control unit fails to operate the vents, as air flow is directed only through the windshield vent and stays hot. do you have any suggestions?