Would a bad oxegen sensor cause sputtering?

I have started getting some sputtering when I initially take off in colder weather. Also it tends to do it worse when there's more pressure on the engine like inclines.

 

I would go out on a limb and say that probably you need either to change your spark plugs, or the coil pack.

When the O2 sensor goes bad the car either runs rich or lean, but it doesn't sputter.

 

Time for VAGCom.......And tune up....

BTW-- it would be helpful if you told us what year and motor you have!

 

Do you have CEL on?

 

2002 A6 3.0

CEL is on, it's coming back as P0421

 

Did some research on that code and it could/most likely is the Cat. so my question is this ...

I have 75K miles on the car so it is under the 80,000 federal #, the car is a 2002 model so what date do they use for the 8 year mark?

Also do I have to carry it to the dealer to get the Cat replaced under the Federal emmissions warranty or can an independent mechanic do it?

 

80000, 8 year starts on the day of the initial service. So if you or the original owner bought the car on say 10/2001, it should be good until 10/2009. As for the dealer, non dealer question, why wouldn't you have the dealer replace it if it is covered under the warranty? I would.

This exact code happened to my car and this is what they did. They tried to set readiness code first. It did not set. If it did, they would have reflashed the ecu for a small fee to $350 or so and called it done. (There is a TSB on this topic.) Anyways, since the readiness code did not set, they replaced the cat under the warranty. Then the code went away. A couple of months later, the code came back. They said it was the ECU threshold being too low in conjunction with O2 sensor being old, but not bad. Reflashed the ECU with the latest update and it has been about a year without an issue.

Anyways, if I were you, I would take to car to the dealer, have them address the catalytic converter and flashe the ECU at the same time. I would be firm that the flash should be covered under the federal warranty.

 

Mainly because there isn't a dealer close to where I live, the closest one is about an hour away.

Thanks for the response.