Oxygen Sensor '04 Tahoe

[anchor man]

Just got off the phone with the mechanic and need two new oxygen sensors and a fuel filter. He said with today's ethanol levels in fuel it's very common for sensors to go bad. That may be the case, but I only have 45k miles on the truck. Should this be happening so soon? Not a big fan of spending over $600 on parts/labor for a vehicle about a year past the warranty.

Thanks, now I feel better

[JollyJoker]

Anchor man

Check your warrenty, the o2 sensors should be covered to at least 50,000 miles if I remember right?

[Jeremy airjer W]

Is there a problem with the vehicle or did the guy just call up and say you need a couple of O2's. If the later is the case then get a second opinion!

I'm betting there is a check engine light on with a lean both banks code. If this is the case get a new mechanic. These codes are more often than not solved by replacing a leaking intake gasket. These have become very common at our shop in the last couple of months.

Jolley is correct most emissions warranties go way beyond the vehicle warranty. The pamphlets included in the owners manuel packet should shed some light on the emissions warranty coverage. Or a call to the dealer will clear things up as well.

[anchor man]

Airjer,

The engine light came on, it was running rough at idle, and the fuel efficiency was reduced by nearly 50%. He said one sensor was completely shot, and the other was giving a very inconsistent reading and on the way out. I'm going to call the dealer to check on the warranty now

Thanks

[Scott K]

airjer is right these are fairly comon for intake gaskets, and replacing an o2 sensor is very seldom the fix for lean codes. As for ethonal damaging the sensors, I dissagree with that. Running e-85 in a non e85 vehicle will cause a lean condition, but I havent seen it cause perm damage to o2 sensors.

[anchor man]

I just talked to the dealer and the warranty only covers the converter and the power intake manifold or something along those lines, but they did verify that the sensors were not included.

[Jeremy airjer W]

I have seen 1 O2 cause a driveability problem in 13 + years. Can it happen sure can. Would I check for a vacuum leak first, absolutely!

Running rough at idle is one of the symptoms for a leaking intake.

As far as the Ethonal vs O2 sensors myth in my opinion its just that!!

[anchor man]

I already told him to go ahead with the repair earlier. If the intake gasket was the problem and not fixed, will the issue re occur shortly after I start driving it again?

Thanks

[Jeremy airjer W]

If it is the intake the new O2's will make no difference.

Its there diagnosis and they need to stand behind it if it doesn't take care of it!!!

[anchor man]

Sounds good, thanks for all the info.

[wannaeye]

I had the exact same problem on my 2003 Silverado, rough idle, terrible gas milage. Check engine light on. Had 1 bad O2 sensor replaced and it's running great ever since. Mechanic told me this is becomming more common with vehicles around 50k miles, for whatever reason???

Good Luck, things should be OK.

[BoxMN]

I just had bank one O2 go on 98 k1500 with 160k. Always ran the same, but light was on. Cleared the code, light came back on. Code said bank 1 (I think, drivers side) Since the repair no problems or lights yet. Mechanic/friend looked over the entire underside (of truck, ha!) for common things, and said she looks in really good shape. Ready for the next 150k

[Jeremy airjer W]

As luck would have it I had an 04 sierra come in tonight with a check engine light and approximately 55k. It had a code for O2 sensor low voltage bank 1 sensor one. No driveability complaint. A quick scan of the engine data revealed the O2 voltage at 0 volts. Unplugged the 02 and voltage went up to 430 +/- millivolts which it should, score one for the PCM. I ran two test lead to the signal wires and completed the circuit with my fingers as the resistance and voltage peaked, score 2 for the PCM. Knowing that the PCM returned to a default voltage and peaked with my finger test I can be relatively confident that the PCM and the wiring to the O2 are good and that the O2 is the source of the problem. Replacing the O2 solved the issue for this one.