AFR gauge says super rich

Joined
Jan 22, 2016
ok i feel i have some kind of bad luck i took her out yesterday drove out to the lake no issues there and back about three hours after we decide we want dinner so we go out to get food and i notice that the afr gauge is reading 10.0 steady....just idling or cruising, i even gave it a little gas a little hard acceleration like half a second the gauges reading fluttered it changed kinda then when back to 10.0 it normally runs at 14.7-15.3 while at idle or cruising unless im wot .... now i assumed it was just a hiccup because occasionally when its cold outside the gauge wont even register until the car warms up then i have to reset it to get it going i assumed this cause while driving it didnt seem like it was running super rich so i was like i will look at it tomorrow jump to this morning i go outside hook the laptop up to the ecm and start her up she drops right down to 10.0 even after warming up she stays at 10.0...i attached a power logger file that shows a little of whats happening i checked my fuel pressure gauge under the hood and it seems normal i checked the air intake filter maybe it was bad needed a new one nope no change when i removed it so any help on trouble shooting help would be great
 

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I see that your narrow band is switching from rich to lean according to the X-counts recorded by your data logger. It seems lazy,but it is switching. This tells me that your wideband is not reading correctly. The other thing that would happen,if you actually had an A/F ratio of 10.0/1 at an idle,is that it would chug very badly. It's idling very smooth. Does your wideband have a calibration procedure that you could perform? Do you use any leaded gasoline?
 
It does look like you are running rich. Noticed your 3rd gear switch is enabled and the service engine flag is enabled.
 
Narrowband is switching, so the AFR is probably actually in the mid 14's.

I would say something is wrong with the wideband signal.

Capture11.JPG
 
I see that your narrow band is switching from rich to lean according to the X-counts recorded by your data logger. It seems lazy,but it is switching. This tells me that your wideband is not reading correctly. The other thing that would happen,if you actually had an A/F ratio of 10.0/1 at an idle,is that it would chug very badly. It's idling very smooth. Does your wideband have a calibration procedure that you could perform? Do you use any leaded gasoline?
I'm running e85 Only and there is a selection for e85 on my gauge I just discovered that today and I'll look for a calibration in the manual for the gauge also where would to wideband be all of the modifications to vehicle where done before I bought it
 
if it was working before, and its not now, then its not a configuration issue. I would try replacing the sensor. My PLX says 14.6 at key on and slowly changes as the sensor warms up.

Bob
 
the thing is i assume its still running fine since it still runs smooth i just have terrible luck when it comes to my cars so i wanted to make sure something didnt really break like the ecm or something
 
Thanks guys for all the help you guys provided I believe like suggested it's the o2 sensor so after dropping one he'll of a shiny penny I have ordered a new one from plx the same brand my gauge is from
 
if it was working before, and its not now, then its not a configuration issue. I would try replacing the sensor. My PLX says 14.6 at key on and slowly changes as the sensor warms up.

Bob
ok well i replaced the sensor well while it wasnt the exact same sensor from plx i went and grabbed one from a local parts store using a part number from bosh its lsu4.9 wide-band sensor i bought another but had a different plug so i wired it to the old plug just to see if the sensor was the problem when it was all said and done it seemed to fix the problem the sensor was steady and after taking a test drive to the store it seemed ok it was acting normal with normal readings on the gauge but once i started my return home it stopped working again back to 10.0 to 1 and, now im stumped could it be a bad plug? not just sensor or could the whole harness be bad ?
 
ok well i replaced the sensor well while it wasnt the exact same sensor from plx i went and grabbed one from a local parts store using a part number from bosh its lsu4.9 wide-band sensor i bought another but had a different plug so i wired it to the old plug just to see if the sensor was the problem when it was all said and done it seemed to fix the problem the sensor was steady and after taking a test drive to the store it seemed ok it was acting normal with normal readings on the gauge but once i started my return home it stopped working again back to 10.0 to 1 and, now im stumped could it be a bad plug? not just sensor or could the whole harness be bad ?

Could be a controller issue.
 
If you had to swap the plug are you sure the sensor was the right one? I thought the 4.2 and 4.9 sensors were not interchangeable even if the plug was swapped. The 4.9 is supposed to be a more " robust" sensor but it means up grading your controller
 
If you had to swap the plug are you sure the sensor was the right one? I thought the 4.2 and 4.9 sensors were not interchangeable even if the plug was swapped. The 4.9 is supposed to be a more " robust" sensor but it means up grading your controller
Yes I used a bosh part number to order the lsu4.9 o2 sensor I was told by bosh the 17018 is the lsu4.9 but when I pulled the old one it look slightly different and the obvious plug difference but when it was hooked up it worked .... For a minute. But I have the one from the plx kit on the way should be here today at some point Also it's possible I haven't checked yet but it's possible the the wires melted cause I couldn't properly protect it from the heat so that could have happened and the new o2 sensor that is showing up Will be the right one and not all hacked up
 
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