02 sensor bypass

[07GTS]

i wouldnt run a stock LS open loop without dialing in the VE table and fail the maf, in stock form they are not dialed in so just disabling the 02 feedback wont end well

 

[Immortality]

PS: o2 sensor and/or cat problems can be caused by coolant leaks, wrong oil (too much zinc), wrong type of silicon gasket sealer used, etc… A well running engine will see cats and o2 sensors last the life of the vehicle (multiple decades)… o2 sensor issues can also be due to wiring, earthing of ecu faults… Simply chucking parts at the car can be a very very expensive way of finding what the root cause is…

I'm gonna disagree with just the bit about O2 sensors lasting the lifetime of a vehicle, sure they will continue to operate but over time they can become lazy and have the engine running less than optimal.

 

[Skylarking]

I'm gonna disagree with just the bit about O2 sensors lasting the lifetime of a vehicle, sure they will continue to operate but over time they can become lazy and have the engine running less than optimal.

It may be true that our o2 and cat sensors become lazy over time but it may also be caused in part because of the chemical crap we sometimes have added to our fuels (as the fuels composition isn’t tightly regulated.).

Heck I’ve heard that paint stripper was sometimes added in rather low concentrations (probably as a method of disposal)… We aren’t told much about the additives fuel companies use but we do hear vapours from some silicons will kill o2 and cats…

For example my daily is supposed to run well on 91 and most of the time it runs very well on this lower grade fuel. But every handful of fills, I get pinging under load because the 91 is crap on that occasion. That can’t be great for o2 sensors or the cats long term. On its own in a one off situation it‘s probably no problem at all but over time it’s like the cut of 1000 knives. Eventually such things will make sensors and cats lazy and eventually kill them

I‘m sure vehicle manufacturers know the truth based on o2 sensor sales in different markets with differing fuel standards but they don’t tell.… Heck, GM/H tells us any noises one hears including piston slaps and rattles are “normal” (and they even tried to blame fuel when their injectors started to poo themselves) so it’s not as if they have an impeccable record of truth telling And BP is really trustworthy with good engineering in its deep sea wells so nothing to worry about there either

PS: a catalyst by definition isn’t consumed or degraded during the chemical reaction it’s used for so it must always be contamination that kills it O2 sensors use catalyst type of reaction (in that they are not consumed) that can also suffer from contamination, not just from the exhaust but even from the atmosphere side of the sensor*). The real question is whether the contamination is the cause of the lazy sensor and vehicle manufacturers won’t say

* there is a type of o2 sensor that doesn’t need to be open to atmosphere for it to work so doesn’t suffer from atmospheric contamination but no idea if it’s widely used in ICE.

 

[apollo13]

It may be true that our o2 and cat sensors become lazy over time but it may also be caused in part because of the chemical crap we sometimes have added to our fuels (as the fuels composition isn’t tightly regulated.).

Heck I’ve heard that paint stripper was sometimes added in rather low concentrations (probably as a method of disposal)… We aren’t told much about the additives fuel companies use but we do hear vapours from some silicons will kill o2 and cats…

Was a long time ago, dodgy servos put toluene in petrol, as it was cheap and has high octane rating. Unfortunately being aromatic, it would bugger up something or other.

 

[Immortality]

I believe that is one of the additives in petrol now they no longer use lead. It plays havoc with older style rubber hoses used in fuel systems. We saw some issues with that when NZ went lead free, they had to re-formulate the lead free fuel as there were a number of engine bay fires caused by it.

Lead contaminates O2 sensors, they don't like coolant either.

 

[Pollushon]

I'm gonna disagree with just the bit about O2 sensors lasting the lifetime of a vehicle, sure they will continue to operate but over time they can become lazy and have the engine running less than optimal.

O2's are definitely consumables, it's inevitable, just with a factory tune they're fine to failure. I like to do mine 80k a throw, 50k on Betty. Then validate readings with a wideband. It's cheap preventative too

 

[greenacc]

I read a product data sheet from Bosch I think it was and it said their O2 sensors, which were the ones Holden put in VEs last 240,000km. Whoever says they last fire is smoking something.
My first one died at 220,000 from memory. I ended up replacing 3 of them as I was guessing which one was causing the fault code. Now it's done 300k and the 4th O2 still has not thrown a code.
Lesson learned: buy a code reader instead of replacing parts that are still working!

 

[Fu Manchu]

I’ve seen people put them in an ultrasonic cleaner. Not sure if cleaning them is ok?

 

[Skylarking]

I read a product data sheet from Bosch I think it was and it said their O2 sensors, which were the ones Holden put in VEs last 240,000km….

Average mileage is 15,000kms per year so that 240,00kms relates to around 16 years of driving. That’s probably what many would consider “decades”.

… Whoever says they last fire is smoking something…

fire? Autocorrect ?

 

[greenacc]

Average mileage is 15,000kms per year so that 240,00kms relates to around 16 years of driving. That’s probably what many would consider “decades”.

fire? Autocorrect ?

Autocorrect is such a piece of 'cardboard'.
Forever was the word that went missing. I'd say most VEs are past the 240,000 km mark by now so replacing these must be expected.