o2 sensors bad?

[KY3TS]

2004 coupe start to run rough. would not go over 2500 rpm for about 5 minutes in any gear (6mt). I turned it off-on, and it never repeated the problem.

When i took it to dealer, they said the front o2 sensors were bad.

Car runs fine now, is the dealer just trying to get over on me?

thanks

[tollboothwilley]

Not likely. Theye probably hooked it up to the OBDII scanner and read the codes that were there. If it happens again take the car to checker/autozone and have the codes read. Then you can post them up here and we can back up what they are saying.

How many miles do you have on you car? Normally 02 sensors don't go out until about 120K +.

[KY3TS]

Car has 32,00 miles on it, the warranty ran out on time in November.

[tollboothwilley]

what year is your car?

warranty is 4yr/60K milespowertrain is covered 5yr/70K miles

[tollboothwilley]

I'd be VERY surprised if the O2 sensors went bad at 32K miles. I have 136K miles right now, and original sensors.

And...when the sensors go bad, its generally the heated ones, which are AFTER the cats.

[KY3TS]

My G is a 2004 that had 32000, when I got, now has 38,000.It was 4 years old in Novermber.I did not get a CEL or SES light, when the episode happened.The deal said the codes where P1271,P1281.

It just seems odd to me, that it is an easy, but expense fix.$183 each for sensors and 4 hours labor.

thanks for all help

[tollboothwilley]

sadly the pre-cat O2 sensors are much harder to get to but dont go bad NEARLY as often.

Are you mechanically inclined or at least willing to try?

Its not too bad, and you can find the 02 sensors for cheaper than that

http://www.infinitipartsonline...gid=0

if you are willing to make a few wire splices, then you can get them for about $65 buck a piece... out the door for $130 if you do the work yourself

[KY3TS]

I can get "plug and play one" for $65.00 each at autopartswarehouse.com.

Just hate to replace good parts.

Guess I will replace them and caulk it up to experience.

I am going to do the brakes anyway, so I will have the car "up" in the air.

thanks again

[tollboothwilley]

sweet

I hate replacing parts, and its weird to have your O2 sensors go bad so early, but if you can get them and do it yourself you'll save a ton of money at least.

Your SES light is still on right? If the light isn't on anymore I wouldn't worry about it if it was just a one time fluke type thing.

$65 is cheap for a plug/play sensor for ANY car. Good find there.

Make sure you have the notched socket for removing 02 sensors.

[KY3TS]

No CEL or SES lights at all. even when the problem was happening.

[tollboothwilley]

Thats weird.

I wouldn't replace until you get a light.

Thats one thing that will kick an SES light if its out of spec. If it just happened once and it was stored in the ECU but never happened long enough to really kick the light I think you will be fine with not replacing.

I'd reset the ECU just for kicks and giggles.

[KY3TS]

Thanks

[Jacko3]

I don't understand how a car can be driven with 32K in 4 years. Thats like 8K miles a year. That is incredibly too small a use for a car that likes to be driven hard.

Anyway, My advice is for you to wait until the SES light comes on again, and permanently. This may have been a one-time incidence. Secondly, as Toolboothwilley suggested, go get your car reset and retuned with the dealer's computers. In fact, they may have done so, but just go back and tell them to reset all the parameters again. Resetting it could help to keep the problem at bay. In the service manual, retuning the G is highly recommended, I think somewhere between 60 k - 80 k miles ( I am not sure). So, maybe your car is telling you to get it retuned. Those pre-cats are pretty darn good and it is rare to find one with problems at such a low mileage.

[Todd157k]

Two ways it can go.. and from what you describe, it would be running really rich. There would be BLACK soot on the inside of the tail pipes. The other way it could go would be really lean in which case it would stumble off the line. If the exhaust soot is grey, it isn't the o2's. You can also compare the two.

[GvilleG35]

New Member

I have a 2004 G35 with 101K. Car is running fine, but gas mileage seems low. I am getting about 15 to 20 depending on how I drive.

If I replace the O2 Sensors will the gas mileage improve?

How easy is it to replace the O2 Sensors? I am willing to try if necessary.

[tollboothwilley]

There are 4 o2 sensors. 2 in the exhaust manifolds and 2 just after the catalytic converters.

The sensors just behind the cats are easy to get to. They are also more expensive.

If you have a cat that is going bad it can help to put new O2 sensors in, but if they are not bad it will not likely help at all.

Have you done any mods to it yet?

I've got 135K miles on my car and haven't needed to change my O2 sensors yet. I'm also running high flow cats.