O2S2 Voltage Always Zero

[bhaugen2]

Originally Posted by steve99

Yes for some reason it appears the ecu is getting feedback that engine is running lean ie P0172, as its getting feedback that its lean it will be adding the maxium amout of enrichment it can via fuel trims which is over 30% most likely causing a very rich condition.

As above poster said you rearly need to diagnose the issue, simply scaling the maf to compensate for another fault , if thats the case, will not solve your problem

.

Great video! That helped me a lot. Still need to watch part 2, but based on part 1 and the graph above (along with RPM) most likely a vacuum leak

[steve99]

Originally Posted by bhaugen2

Great video! That helped me a lot. Still need to watch part 2, but based on part 1 and the graph above (along with RPM) most likely a vacuum leak

you can get same effect with cracked header or gasket leak in header before or near 02 sensors. At ilde and low rpm you will get fresh air sucked in between exhaust pulses. so gives you perceived lean condition and high positive fuel trims, but as rpm increases enough exhaust pressure to keep out fresh air and the trims go back to normal at higher rpm.

[Kodename47]

Originally Posted by steve99

Yes for some reason it appears the ecu is getting feedback that engine is running lean ie P0172, as its getting feedback that its lean it will be adding the maxium amout of enrichment it can via fuel trims which is over 30% most likely causing a very rich condition..

P0172 - System Too Rich (Bank 1). It's the opposite to above. The system is at maximum negative trims.

P0171 is for lean condition

[steve99]

Originally Posted by Kodename47

P0172 - System Too Rich (Bank 1). It's the opposite to above. The system is at maximum negative trims.

P0171 is for lean condition

haha only one off :-)


im going to put my money on that electronic maf bender box if its in use

[bhaugen2]

Originally Posted by steve99

haha only one off :-)


im going to put my money on that electronic maf bender box if its in use

That is what I'm thinking as well. I'm going to see if I can get the stock CAI shipped to us and then see if that fixes it.

[ChesterV]

Is there any update on this if it ever got fixed? I'm having the same issue. Completely stock except on UEL catless header

[Turdinator]

Originally Posted by ChesterV

Is there any update on this if it ever got fixed? I'm having the same issue. Completely stock except on UEL catless header

Do you have a tune to suit the UEL catless header?

[JoweeHolmes]

Originally Posted by bhaugen2

That is what I'm thinking as well. I'm going to see if I can get the stock CAI shipped to us and then see if that fixes it.

Hey! Same issues right now, any tips on how you got this fixed?

[Compelica]

This happened to me when I accidentally flashed K00G to a prefacelift, when it was meant for the facelift. From Techstream the 2nd O2 sensor voltage would not budge, and it gone away when I flashed back to A01G.

Far from the solution but I hope it helps someone.

edit: and I found this
https://www.ft86club.com/forums/show...postcount=1047