Extremely low O2s

[MauDeuce50]

At WOT my O2s are way too low.. Getting knock. O2s will also stick at 000 for a few secs at very low to no throttle. There is a good chance that the Knock could be a separate issue like motor mounts or something, My tps is around 4 at wot, but perfect at .42 at idle. Here are the mods: parts store fuel pump, hotwire kit, TT 5.6 chip, afpr with 38# of fuel pressure, MAF pipe with K and N, no cat, dual atr mufflers, stock boost supposedly . Has a working knock sensor, and brand new O2 sensor... Can somebody tell me why my O2s are so low? I tapped on the MAF and it didnt affect the idle. Here is a video if that helps, just skip to about 1:30 and that is where my tests are.

Any input is greatly appreciated!

 

[getdowngranny]

Do you have any way to monitor boost and fuel pressure? I would verify how much boost you are getting and that fuel pressure is rising 1:1. It looks like you are leaning out the motor. I would quit going WOT till you verify what I stated above.

 

[MauDeuce50]

Do you have any way to monitor boost and fuel pressure? I would verify how much boost you are getting and that fuel pressure is rising 1:1. It looks like you are leaning out the motor. I would quit going WOT till you verify what I stated above.

Yeah i am going to grab a fp gauge today if I can and I will post results

 

[getdowngranny]

Also. When figuring the above stuff out. You need to do the WOT pull in third gear with a good load on the motor. It will eliminate the transitional knock and give you a better idea of what is really going on.

 

[MauDeuce50]

Also. When figuring the above stuff out. You need to do the WOT pull in third gear with a good load on the motor. It will eliminate the transitional knock and give you a better idea of what is really going on.

Ok thanks a lot ill do that

 

[MauDeuce50]

Ok thanks a lot ill do that

Also. When figuring the above stuff out. You need to do the WOT pull in third gear with a good load on the motor. It will eliminate the transitional knock and give you a better idea of what is really going on.

In drive im guessing?

 

[getdowngranny]

Yes but make sure you are going fast enough in "D" so that it won't down shit into 2nd. I would get to around 30-40 mph first then go WOT.

 

[MauDeuce50]

Yes but make sure you are going fast enough in "D" so that it won't down shit into 2nd. I would get to around 30-40 mph first then go WOT.

Right, ok ill post the results hopefully later tonight. Thanks!

 

[getdowngranny]

What brand o2 sensor did you put on there?

 

[MauDeuce50]

What brand o2 sensor did you put on there?

Bosch, but it still had the low o2s with the stock one too. and I got around 55# of fuel pressure at WOT, but my fp at idle was like 34 with line on and 42 with line off.

 

[MauDeuce50]

Bosch, but it still had the low o2s with the stock one too. and I got around 55# of fuel pressure at WOT, but my fp at idle was like 34 with line on and 42 with line off.

And my scanmaster showed 007 milivolts and 4.6 kr

 

[getdowngranny]

Do you have a real boost gauge (not the factory one) to see how much boost you are getting at WOT?

 

[getdowngranny]

Also. Post all of your scanmaster numbers at idle after warm up.

 

[MauDeuce50]

Also. Post all of your scanmaster numbers at idle after warm up.

Sadly i do not have ab actual boost gauge, and i will post my #s shortly

 

[HouTX87]

Yes but make sure you are going fast enough in "D" so that it won't down shit into 2nd. I would get to around 30-40 mph first then go WOT.

I think you'd probably have to be going faster than 30-40 to stay in 3rd at WOT. I'm thinking more like 70+. I want to say my 3rd gear test pulls on the highway are usually from about 70 to 90 unless I have plenty of road .

 

[getdowngranny]

I think you'd probably have to be going faster than 30-40 to stay in 3rd at WOT. I'm thinking more like 70+. I want to say my 3rd gear test pulls on the highway are usually from about 70 to 90 unless I have plenty of road .

I was saying to go WOT after you have at least reached 30-40 mph first. That way it doesn't downshift.

 

[MauDeuce50]

Ok here are my #s:
O2: 761 but steadily decreasing the longer the car sits
KR:0
AF:4
LB:31
Bat:13.5
Int:128
BLM:142
Clt:173
Ats:118
Rpm:775
Tps:.42
Iac:5
Cc: 115
Mal:0​

 

[69RSCLONE]

Could be plugged injectors. Mine were full of rust and even after spraying them out with throttle body cleaner they only flowed 24lbs. After I had them professionally sonic cleaned they flowed 31lbs. My BL at idle were 150 and gained KR midway through 2nd before the cleaning. Not right off the line. But it's an idea.

 

[MauDeuce50]

Could be plugged injectors. Mine were full of rust and even after spraying them out with throttle body cleaner they only flowed 24lbs. After I had them professionally sonic cleaned they flowed 31lbs. My BL at idle were 150 and gained KR midway through 2nd before the cleaning. Not right off the line. But it's an idea.

Hmm ok thanks! I will look into that as soon as I get an accurate boost gauge

 

[we4Mateo]

BLM's are high so either it's adding fuel falsly from a bad O2 or you have a fuel supply problem.