Analog AFR gauge question.

I installed custom boost and AFR gauges after installing a Magnuson super charger on my 2020 Sport. I was expecting to see a steady needle but instead it jumps all over the place. When I talked to the vendor they told me they must have shipped my gauge before a recent software change so send it back to them to be reprogrammed. After getting the gauge back I still had the same issue and this time they said they would build me a new gauge. After receiving the new gauge I STILL had the same issue so they promised to ship me a new O2 sensor and cable. Well, I just finished installing the new O2 sensor and cable and it still doesn't seem right to me.

Can anyone tell me how I should expect the needle to act? It just seems to be too erratic to me but this is my first AFR gauge so I'm starting to doubt myself. I took some videos but apparently those cant be uploaded.

 

AFR is best read digitally. It's an erratic number that changes rapidly with throttle, load, and boost, unless you're just cruising it's gonna move and in my opinion would be useless and annoying as an analog gauge

 

You can upload to youtube and post a YT link to share video.

What do you mean by "jumps all over the place"? How much does it change?

AFR shouldn't move erratically more than a few tenths of a point. If the AFR value is jumping around more than 1 AFR point you would feel it, the ECU would be making ignition timing changes and/or would trigger a CEL/DTC. AFR usually will be near 14.7-14.9 under low load/cruise, bouncing back and fourth a couple tenths of a point. Under heavy load/WOT, it should go to a rich condition. Not really sure how rich with the 2GR-FKS and boost. 11.5-12?

Which sensor and gauge? How and where is the sensor installed?

 

This is what I was afraid of.

Here's the video I took after the original installation. This is what I sent to the gauge builder and they didn't think it looked correct either.

https://vimeo.com/manage/videos/740562687

Here are three videos I took tonight.

https://vimeo.com/manage/videos/740563980

https://vimeo.com/manage/videos/740564056

https://vimeo.com/manage/videos/740564122

 

This looks kinda like what I'd expect, I don't have any videos of my cars old AEM digital gauge but the numbers changed very rapidly and getting on and off the throttle makes them change a ton. On a flat section of highway use your cruise control and see if it still flicks to 16 sometimes, that's the only thing that looked weird to me but it might just be how they work with the tune and new toyota engine management you have too,

 

Is the factory sensor wideband? The ecu data stream samples fast enough to see those AFR changes if they are real, maybe worth something for a reference.

 

It is on all V6 Tacomas after year 2000

 

Log it and compare to the analog.

If the AFR swings in op videos are real I can't believe he wouldn't feel torque changes. What happens on a WOT pull?

 

AFR doesn't have a great effect on power output compared to timing advance. I can believe you wouldn't feel it at all.

 

Sure, but it still has a noticable effect to the driver if holding a steady throttle position and timing advance should be reacting to AFR going that lean, pulling timing erratically. It's going from 14-ish to pegged at 18+! If that was a real number the engine wouldn't be happy, that's if it didn't cut out completely until fuel returned. The needle behavior almost looks like a loose ground wire or something.

If op gets back maybe they can provide more info about what kind of sensor/system and where the sensor is installed.

 

It does seem like it has a loose connection somewhere but it wasn't happening along with bumps or anything. That said a spike to 16 isn't gonna stall, I set cruise AFR near 15.5 on my own tunes. When the needle buries itself in the far right on his gauge it is because the ECU is engaging fuel cut, you can hear he's let off the throttle.

 

Oh, I have no sound on the videos. I assumed op was holding steady throttle otherwise it's kind of useless info if they are modulating the pedal.

 

Ya, they were some quick videos close to my house not really knowing what I should be looking for. I DID notice that when I backed all the way off the throttle the needle would peg at 18.

I’ll go out tomorrow and see how it acts at a steady throttle using the cruse control.

 

When you let off the pedal the ecu stops injecting fuel until engine rpm falls closer to idle (at least with a manual transmission)

CC probably not necessary, just hold the throttle steady on a flat stretch of road so that you are not accelerating or decelerating. If you're comfortable with it, do a WOT or at least a swiftly accelerating run, too.

 

Gotcha. I’ll give that a try.

I DO have a manual. I’m assuming this would be best in 4th?

Thanks.

 

Depends on the road and how fast you want to end up going. 3rd seems like it would be ok.

 

Yup, I'm thinking it's just the nature of the beast? I get a steady needle at WOT and the needle pegs at 18 when decelerating. Holding steady in 3rd gear with CC gives me a jumpy needle. I'm not sure I can live with this. Like stated above; pretty annoying.

https://vimeo.com/manage/videos/740876233

https://vimeo.com/manage/videos/740876007

 

Where is the sensor installed?

 

Right bank between the cat and OEM O2 sensor.

 

I’m sorry, but what?
You bet your buns AFR can affect power output.
Being too rich leaves a ton of unused power on the table.
my last procharged mustang was 11.0 at WOT. Without touching any timing - just the fuel tables - and leaning it out to about 12.1 at WOT, I picked up over 30 whp on the dyno.

OP - did you calibrate the sensor BEFORE threading it into the bung?

At idle, you should be at stoic - 14.7

steady cruising/part throttle it should fluctuate somewhat, but not a whole lot. By somewhat I’m meaning 0.5-1 fluctuation