Oxygen Sensor help........

[dojrs]

i SCANNED MY obdii and came up with a bad O2 sensor code a while back. changed the O2 upper bank sensors my rear sensors are programmed out. fast forward to two days ago I'm still getting the O2 sensor code. says heater faulty. I'm running long tube headers, 523 lift cam, and custom exhaust to make a short list of whats done mechanically. im guessing since I don't have any cats my upper bank O2 sensors aren't getting hot enough to read properly. Am I making the correct assumption here ?? anyone know anything i can do to fix this without putting cats back on ? currently Im just clearing the code when it trips the check engine light.

 

[exp500]

Vehicle specifics first. Some have had luck using extenders / adaptors. Denso sensors.

 

[dojrs]

Vehicle specifics first. Some have had luck using extenders / adaptors. Denso sensors.

2005 tahoe, 5.3, 520 lift summit cam, trunions upgraded, new push rods, new oil pump, chevy performance valve springs, 1 7/8" long tube headers (cant rem brand - amazon they were cheapo's), 40 series flowmaster, new fuel pump. computer was re-programmed to accomodate the cam & everything.

 

[Tonyrodz]

What brand O2 did you go with? Is the code telling you it's the same one that's bad?

 

[dojrs]

What brand O2 did you go with? Is the code telling you it's the same one that's bad?

I honestly dont remember the brand name of the O2 sensor I bought. Im not certain of the specifics of the code prior to me changing the sensors. The mechanic who re-programmed my ECM for the cam swap told me the O2 sensors were bad when I picked it up from him. I saw a youtube video yesterday of a gentleman who changed the O2 sensors in a totally different vehicle and it was having the same issue. The lack of catalyttic converter kept the exhaust temps cooler causing the O2 sensors to have a fault code. mine shows an O2 heater code fault.

 

[Tonyrodz]

I honestly dont remember the brand name of the O2 sensor I bought. Im not certain of the specifics of the code prior to me changing the sensors. The mechanic who re-programmed my ECM for the cam swap told me the O2 sensors were bad when I picked it up from him. I saw a youtube video yesterday of a gentleman who changed the O2 sensors in a totally different vehicle and it was having the same issue. The lack of catalyttic converter kept the exhaust temps cooler causing the O2 sensors to have a fault code. mine shows an O2 heater code fault.

Strange. I've been running with no cats or down stream O2's for probably 4 years, and I've never had any problems with them. I just changed the one because it was lazy--but not setting any codes.

 

[exp500]

Run an extender and Denso O2, 1/2-1 inch long, can use 90 degree if not enough room. Check wire length first. If it works wirhout throwing code it's about a 2 MPG improvement. Cheap fix.

 

[Tonyrodz]

Run an extender and Denso O2, 1/2-1 inch long, can use 90 degree if not enough room. Check wire length first. If it works wirhout throwing code it's about a 2 MPG improvement. Cheap fix.

Could you explain? I'm not understanding this. This goes for anyone? Get the O2 out of the exhaust stream?

 

[exp500]

Tony- Yes. it allows the heater to be more efficient. The only downside is the timer that sets code. Sometimes it doesnt work. about a 50/50 chance, but $15 fix.I havn't looked ino the programming yet. I've been successful 6 times of 11 tries.

 

[dojrs]

Tony- Yes. it allows the heater to be more efficient. The only downside is the timer that sets code. Sometimes it doesnt work. about a 50/50 chance, but $15 fix.I havn't looked ino the programming yet. I've been successful 6 times of 11 tries.

can you upload a pic or link to one of these extenders

Run an extender and Denso O2, 1/2-1 inch long, can use 90 degree if not enough room. Check wire length first. If it works wirhout throwing code it's about a 2 MPG improvement. Cheap fix.

ok I'm even more confused i think at this point. how would placing an extender onto the O2 sensor cause it to be warmer?? I'm thinking if you place an extender on the O2 sensor it will cause it to be further from the exhaust gases and thus cause it to have a lower temperature..... I'm not a mechanic just thinking of it like a hand in proximity to a pot of boiling water. the closer the hand is to the water the hotter it will be. further away the hand is the cooler it will be.

 

[exp500]

No research, cheap results. My understanding is the timer on the control loop activates after about one minute of out of range difference. O2 sensor, not EGT sensor. (still must be warm to work).Exiending the time would probably fix. Programming I havn't looked at yet. Never tried on rears programmed out.
There are many choices for extenders/Bungs/non foulers. Heres one.
Top Quality M18x1.5 O2 Oxygen Sensor Extender Spacer Car CEL Fix Check Engine Light Eliminator Adapter Stainless Steel New Brand|Exhaust Gas Oxygen Sensor| - AliExpress
Amazon.com: Dorman 42002 Spark Plug Non-Foulers - 18mm Tapered Seat for Select Models, 2 Pack: Automotive

 

[Rocket Man]

Sounds like snake oil to me. Never heard of these “extenders”.

 

[exp500]

RocketMan- thats what I thought too when I first heard it. Seems the Ferd guys were pretty aware of it from stang converter deletes. I guess some were putting resistors inline to show different results too. But using as a fuel trim on our series, and to shut off the light, it works about 1/2 the time.
Cheap and works are pretty high on my list. I'm trying to keep a fleet of old Hi mile work trucks on the road reliably and safely.

 

[Fless]

Here's an example:

 

[Rocket Man]

Here's an example:

Isn’t the system telling you that the sensor is bad? You can run longtubes with no cats and tune the downstream sensors out. The upstream sensors need to be working right in order for the pcm to adjust mixture. If the op is having issues with his upstream sensors my suggestion would be to buy quality parts not the store brand. They should work fine. If not there’s an issue that needs to be fixed not band-aid fixed. My downstream sensors are tuned out, my upstream ACDelco ones work fine.

 

[Rocket Man]

Here's an example:

He even says you should fix your car and not do what he’s doing if you can afford to. This is for a downstream sensor and it’s telling him he needs a new cat.

 

[Fless]

He even says you should fix your car and not do what he’s doing if you can afford to. This is for a downstream sensor and it’s telling him he needs a new cat.

Agree completely. It's just a band-aid.

 

[exp500]

You still need a working upstream sensor. My first post above said Denso. And later spoke of error code timing. Just tryin to help- He's gonna do what he wants. Jeez....

 

[MN-TAHOE]

Isn’t the system telling you that the sensor is bad? You can run longtubes with no cats and tune the downstream sensors out. The upstream sensors need to be working right in order for the pcm to adjust mixture. If the op is having issues with his upstream sensors my suggestion would be to buy quality parts not the store brand. They should work fine. If not there’s an issue that needs to be fixed not band-aid fixed. My downstream sensors are tuned out, my upstream ACDelco ones work fine.

 

[MN-TAHOE]

The O2 sensor seems to be always the "default" code for all issues so I replace the O2 sensor then the other one goes out. Apparently the 5.7 Litre has 4 O2 sensor's so what-replace them all or ignor?