Possible rich condition? Can someone help me read these O2 readings?
#1
Possible rich condition? Can someone help me read these O2 readings?
Truck seems like sometimes it has good power, and other times it feels like i'm driving a Geo Metro.
In a prior thread I asked about my cat, in this thread I've hooked up my scan tool and graphed my O2 sensors as I drive. In the video below I'm on the highway, at about 65 with a steady throttle until the end when I take the exit.
It looks to me like the entire time I'm cruising it's running rich? I'm a novice when it comes to O2 and Air fuel readings so maybe someone here with more experience can tell me if this graph looks... normal?
And this is sitting in park at about 1500rpm
Edit - I should add it's got factory intake, new air filter, no TB spacers or anything. Copper plugs put in about 15k miles ago
In a prior thread I asked about my cat, in this thread I've hooked up my scan tool and graphed my O2 sensors as I drive. In the video below I'm on the highway, at about 65 with a steady throttle until the end when I take the exit.
It looks to me like the entire time I'm cruising it's running rich? I'm a novice when it comes to O2 and Air fuel readings so maybe someone here with more experience can tell me if this graph looks... normal?
And this is sitting in park at about 1500rpm
Edit - I should add it's got factory intake, new air filter, no TB spacers or anything. Copper plugs put in about 15k miles ago
Last edited by Prismatic; 07-08-2020 at 01:25 AM.
#2
#3
#4
Down at idle at a red light
And this is following that same highway route I did before
..And for ishts and giggles, here's the B1 S1 volts vs B1 S1 Short Term Fuel Trim on the same highway route (video starts up when I enter the highway)
I also ran a back pressure test using the upstream O2 port and I saw no meaningful pressure. 0 PSI through 3000 RPM with slight fluttering as I let off the gas, maybe 0.25psi worth.
Here's the upstream O2 sensor
https://i.imgur.com/HiYAj3l.jpg
I don't have full history on the truck but I'd bet dollars to doughnuts that's the factory O2 sensor. Maybe I'll drop a couple new ones in and see how she goes.
Last edited by Prismatic; 07-08-2020 at 08:01 PM.
#7
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#8
I don't have a vacuum gauge on me but here's map and LTFT at idle and 2000 rpm
idle
2000 rpm
Craking event (fuel pump disabled)
And starting event
How can I be drawing more vacuum at 2000rpm? I thought as throttle increased vacuum should decrease?
idle
2000 rpm
Craking event (fuel pump disabled)
And starting event
How can I be drawing more vacuum at 2000rpm? I thought as throttle increased vacuum should decrease?
Last edited by Prismatic; 07-09-2020 at 12:02 AM.
#9
#10
Our sensors measure pressure in inHg Absolute (inHgA), which makes that statement demonstrably false. So, I'll demonstrate.
Here I've removed my MAP sensor from the manifold and attached it to a vacuum pump with an inHg gauge.
As you can see, the inHg gauge reads zero, no vacuum.
The scan tool confirms that at 0 inHg (physical gauge) the sensor reads 30inHgA (sea level)
I draw 15.5inHg vacuum on the sensor
Map sensor reports pressure has fallen from 30 inHgA to 14 inHgA
Draw the vacuum down to 20 inHg vacuum
And the sensor reports 9 inHgA
Here I've removed my MAP sensor from the manifold and attached it to a vacuum pump with an inHg gauge.
As you can see, the inHg gauge reads zero, no vacuum.
The scan tool confirms that at 0 inHg (physical gauge) the sensor reads 30inHgA (sea level)
I draw 15.5inHg vacuum on the sensor
Map sensor reports pressure has fallen from 30 inHgA to 14 inHgA
Draw the vacuum down to 20 inHg vacuum
And the sensor reports 9 inHgA
Last edited by Prismatic; 07-09-2020 at 05:16 PM.