another dumb question on O2 Volts

[thunderace31]

I was just out in my T and made a few WOT pass out on Telegraph, I just change to a Hemco Dog House and a 65mm TB
I used to see 1-4* of Knock at WOT and 740-820 on the o2
Today I got 0* knock But O2 volts were consistanly in the 102-140 range each time. its also like 98* out side!

Car did not seem to pull that hard either.

Now I ask this question because I am still clueless on the whole #'s thing for the o2. I know it cycles and never questioned the 700-850 since I always got that till now.
Now that I am way low dose this mean I am running way rich or way lean??
I am thinking Rich?? So I need to pull a little Fuel pressure out of it ???
Any Help would be great here I just want to make sure I am going the right way. At part throttle the car is super resposive!!! and mid range seems like before the change.
Thanks again guys for the help dont know what I would do without you

 

[Momar]

the lower the number, the leaner you are, the higher, the richer. I doubt you were actually running that lean and not get knock. I am not a pro, but the first thing that comes to my mind would be a problem with the 02 sensor.

Ben

 

[thunderace31]

Well that helps but it has been fine till the hemco and 65mm so it makes no sence

Oh I also header wraped the down pipe to keep the heat up and exaust flowing could this change anything in a bad way??
Thanks agian guys

 

[thunderace31]

Ok checked all the wires and eveything looks fine, o2 looks clean also. There is a small amount of Race Gas in the tank due to a bad tank of gas and lots of know so I added about 4 gal. of Synoco 110 to it. Could this have caused the o2 to go bad ??
Help guys did it again today 149 0* of knock
I am turning up the Fuel Pressue to 50lbs seems high but I guess well see if it helps

 

[Eric Stage I]

I would try a new O2 sensor if you've run race gas through it.

Eric

 

[thunderace31]

Ok now let me throw this out there for you I put one of those dumb poston ent. 145mph speedo deals on with the addapter and damn if I did not due that but 2-3 days before this could it be trowing this all out of wack??
I am so madd that they sell something that causes issues with the computer!!!
I will be getting the Kirban one over the winter and removing this crap tomorrow!

 

[BLACK6PACK]

Change the o2 sensor. They're only $25-30 if you get them from the right place. When running race gas I could get about 4 passes at the track then leave and get about a mile or two from the track before the 02 sensor was shot.

 

[2QUIK6]

What's your O2 cross-counts doing at idle with engine at op temp?
They should be cycling from 0-255 in less than 90 secs.
What kind of O2 do you have?
As said, never hurts to have a spare, so buy another sensor, AC delco or Denso only, and try that...if it aint the problem, then you'll have a spare and trust me, you'll need it sooner than later running leaded race fuel.
The Densos seem to hold up to leaded gas fairly good.

The mods you did should allow more airflow which would make you leaner...but would not make that significant of a difference to cause what you are seeing....
However, I have found with Delco units, it seems like the bottom falls out of them if they get below 600mv or so and read very low like you are seeing. But just replacing the TB and plenum would not make the O2s drop from 800 to 600mv I would not think.

 

[thunderace31]

Even with the heat o2 that is in there??
I though they were better??
I will get a new o2 tomorrow and I all ready removed the 145 speedo as I dont plan to get a new chip till next year when I add an alky kit.
Thanks for all your help

 

[2QUIK6]

Even with the heat o2 that is in there??
I though they were better??
I will get a new o2 tomorrow and I all ready removed the 145 speedo as I dont plan to get a new chip till next year when I add an alky kit.
Thanks for all your help

Maybe installing the plenum you accidentally unplugged the wire for the heated O2 since its gets its power from the EGR??
The heated O2 should handle the leaded gas better, thats what I run now on mine, been thru about 12 gallons of race fuel before I got the alky system and its still the same O2 in it. The heated O2 also drops quickly once the mv get below 600 also.

 

[thunderace31]

I will check that tomorrow also.
Never thought of that one THANKS A TON!!
Also got a 748 an 0* Knock !!! On quick blast a little while ago
But it could be loose

 

[thunderace31]

Ok I put a new O2 in and I am getting all kinds of strang readings still, Was on it one time got 720 and 0* Knock, Next time got 350 but still 0* knock then got 109 and 0* knock, then got 898 and 3* of knock and then from a roll I got 729 and 1* of knock (Guessing on the shift)????
Me lost here HELP!!!

I turned the Fuel pressure up 2 lbs and that seem to have helped some also.

One other thing I wraped the Down Pipe with header Wrape and also the Turbo Exsaust housing just before the Hemco and TB change I did not really see any change then that I can remember.

Looking for help here guys I am a little worried about these #'s

Also looking for info on the wide band O2 and where to get one how much ect.

 

[2QUIK6]

Did you relocate the O2 sensor somewhere after the turbo??
Thats the only time I have experienced wacked out readings was with the O2 in the downpipe as there is significant heat loss going thru the turbo.
The narrow band O2 seems to only work consistantly if its in the uppipe just before the turbo...at least that was my experience when I tried to relocate mine....several people said they even put it down at the bottom of the DP just before the cat, but I could not get mine to work anywhere but just before the turbo.
Also make sure you don't have too much anti-seize on the threads of the sensor to keep it from grounding properly.

 

[thunderace31]

Nope o2 is still in the up pipe same as factory location
Did not even add any antiseize to it so that can not be the problem either.
Thanks though I am really stumped as must everyone else on here???

 

[gbsean]

do you have direct scan or scan master. what were the cross counts. are you sure the plenum and TB are tight no gaskets loose etc. did you accidently knock the knock detector. when you cahnged the plenum was the egr port closed or open.

 

[thunderace31]

I have a Scan master
Cross counts when idel are going from low to high and back.
Couldnt tell you if the egr port was open or closed did know to look at
I have leak checked with carb clean and gas and found no leaks any place.

Also Knock is really 0* here guys I have 100% Verified that.

If I leave boost at 18lbs no knock on the scan master, if I move it up to 20-21 knock out the a$$!! (Still no Knock at 19lbs)

How due I know if the EGR is open or closed anyway?? Should be closed when at idel any way