Code for all 4 O2 sensors popping up

[Danie Lizarraga]

Hello everyone, i'm new to the forum. I hope someone can help me figure out what my problem is. I have a 2000 Tahoe z71 5.7 L, and I've never been able to figure out why all 4 of my O2 sensors go bad within a month or less. I've stopped buying new ones since almost a year and a half ago.

I've bought brand new ones and everythings good for about a month or less then the codes appear. I clear the codes and check after running the miles i need and nothing. Does anyone have an idea as to why I cant get the O2 sensors to stay good?

 

[OR VietVet]

Welcome to the forum from Oregon.

The rear O2 sensors can be dirtied up from cat problems. But I suspect that your ignition system is causing problems. How old are the plugs, wires, cap, rotor, fuel filter as well? Have you checked for vacuum leaks that would cause a lean condition and the sensors are richening-is this a word, the fuel mixture? Air filter? What brand and octane fuel do you run?


We recommend that you put all your rig(s) info in your signature so we all don’t have to guess at year, make, model, engine size, trans, rear axle locker…….etc. While you may have posted pertinent info in your first post, you may forget to do it again and the info is needed by us anyway. Makes it way easier on all members that attempt to help, to have that info right up front. It is also recommended that you take a pic of your RPO codes, on the inside cover of the glove box, and post that image in your signature. All this info will greatly help those that will try to help with a problem.


If there is any other info, like upgrades, mods or recent mechanical/maintenance work done, that would be helpful in any post as well. Too many times a question is asked by the poster and after about 10 responses we find out that the poster has done recent work to attempt to fix the problem or work that was done that SEEMS not related to the problem.

 

[wjburken]

Welcome to the forum from Iowa.

Looks like Ron (@PNW VietVet) has given you some homework. He’s an an old school mechanic and won’t steer you wrong. Others will likely chime in with some other thoughts as well.

 

[Fless]

It would be interesting to see the fuel trims, at idle and at 1500 or so RPMs. Bank 1 and Bank 2, long-term and short-term. If you have or can get a scanner, check those, jot them down, and post them up here.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

You've already got folks assisting you, which is great.

I hope that you will become a participating member in the Forum's discussions.

Pics, please.

 

[swathdiver]

Hello everyone, i'm new to the forum. I hope someone can help me figure out what my problem is. I have a 2000 Tahoe z71 5.7 L, and I've never been able to figure out why all 4 of my O2 sensors go bad within a month or less. I've stopped buying new ones since almost a year and a half ago.

I've bought brand new ones and everythings good for about a month or less then the codes appear. I clear the codes and check after running the miles i need and nothing. Does anyone have an idea as to why I cant get the O2 sensors to stay good?

Specifically, what codes are you getting?

 

[Danie Lizarraga]

Wow I wasn't expecting all the quick responses! thanks everyone for trying to help out so far. i currently have 5 codes, i figured the last code (P0410) was worth asking in this thread as well. I'm still learning how to use this forum so i apologize if a lot of information is missing. If i need to give any more information, do let me know. As for getting numbers while idling and etc that Fless has asked for, i will try and get them tomorrow as early as possible

As for the O2 sensor codes:
P0135
P0141
P0155
P0161

 

[Danie Lizarraga]

Welcome to the forum from Oregon.

The rear O2 sensors can be dirtied up from cat problems. But I suspect that your ignition system is causing problems. How old are the plugs, wires, cap, rotor, fuel filter as well? Have you checked for vacuum leaks that would cause a lean condition and the sensors are richening-is this a word, the fuel mixture? Air filter? What brand and octane fuel do you run?

I recently changed spark plugs and spark plug wires
Fuel filter is maybe a year old
The cap and rotor are a little over 2 years old
i run 89 octane
There are no vacuum leaks (at least that i've checked for)


The same time we changed the cap and rotor, we swapped in a remanufacture long block, but even before that we still had the codes from my post of the codes before.

The cats might possibly be the problem as they were changed approx. 9-10 years ago

 

[OR VietVet]

Sure does seem to point to that picture of cats and sensors. Post pics of the plugs when you can take them out and label them or keep them in order when you post the pics.

 

[Danie Lizarraga]

Sure does seem to point to that picture of cats and sensors. Post pics of the plugs when you can take them out and label them or keep them in order when you post the pics.

Would there be a way to tell if the cats are bad? Also the spark plugs are around 3 weeks old so i'll try to pull if it stops raining here