Okay I'm jumping in feet first......

I have to replace the O2 sensors on my daughters 96 A-4 Quattro....

any "words of wisdom" to an OLD grease monkey ( I put myself through college IN THE 70's) as a mechanic-- but to open the hood today I'm lucky to find the dip stick..... lol

Charlie

 

The precat sensors are pretty easy to change. Just requires an o2 sensor tool, a U joing, ratchet and a long extender. You'll have to unbolt the coolant tank and push it out of the way. On the passenger side you'll have to remove the intake hoses iirc. I hope you are replacing with oem parts and not splicing in generics?

 

I had to replace mine as well =/....

 

jest, are the precat sensors are the only ones that effect mileage and performance?

 

Yes Bentframe , the downstream O2 sensor lets the ECU know the cat is working.

 

Round two...

My dealer told me ALL the O2 sensors had to be replaced... Now it sounds like JUST the two BEFORE the C.C. need fixing... According to the check engine light, I was TOLD ALL the O2 sensors were bad.. Am I getting the "more is better"... Or should I replace ALL 4 at the same time... car has 82,000 miles.

Thanks

Double C

 

sorry to break it to you dude...but our o2 sensors (the 12Vers) are ridiculously expensive....about 125 bucks a piece iirc....i found a site where you can buy just the internals, and reuse the old sensor housings..saves you some big bucks if you're doing all four...if i find it i'll post it up here for you

 

your two front sensors are a three-wire configuration....the two rear sensors are four-wire.....here's the link to the fronts....and here's the rears.....read the full description so you understand why they're so much cheaper than new sensors...

 

Are you going to replace them yourself. You can save a lot of money that way. I would just replace the precat ones first and see if that clears up your problem. No sense in dropping so much cash if you don't have to.

 

Thank you ALL for your help... I will replace the front ones first... Then if that does not fix it, the rears... I am going to sell this car, (and get a newer one -this is my daughters, I have an 03 A-4 3.0 Quattro).. Putting alot into this doesn't make sense (cents lol)

thanks again

Double C