A little concerned about my wideband readings

[BROK3N-SVT]

So today I decided to take my car out and drive it to a friends house. Weather is still bad but a old friend passed away this morning and I decided life is too short not to enjoy the little things.

Anyways....

I just had my tune done a few weeks ago with all of my upgrades in my sig. I did my wideband in the downstream location on the passenger side. I know the gauge isn't going to be that accurate.

When just cruising on the freeway about 70, my gauge is saying about 14. It jump around a very little but but 14 is the average. When I let off the gas and I'm still in gear, the gauge will bury at 20 and stay there until I either hit the gas or push in the clutch. When I'm accelerating and I push the clutch to shift, the gauge will bury itself the other way at 10 until I get back into the gas.

I don't know if this is something I should be worried about. I don't know what it's at when I really lay into the gas because I don't get enough traction in this weather. The tuner has pretty good reps locally with all of my friends big number cars. I sent him a message but figured I would get a second opinion with you guys to see what you thought and if you guys see this also.

Let me know what you think.

 

[Red-GT500]

Mine does the exact same thing. The high reading is because the engine is basically only an air pump with a little gas while you are of the gas. Its rich between shifts because of excess gas after you press the clutch. Shelby American tuned mine the same as their Super Snakes so I dont see it being an issue.

 

[blkGT500nCA]

Your results are similar to mine.

 

[BROK3N-SVT]

Okay. Thanks. That makes me feel so much better.

What kind of reading should I look for a WOT?

 

[blkGT500nCA]

11.3-7ish

 

[BROK3N-SVT]

Thanks. I'll have to wait for a nicer day to check that

 

[rotor_powerd]

Sounds completely normal.


EDIT - As long as it's running fine and fuel mileage isn't terrible, AFR isn't really too much of a concern out of boost. Under load is when it matters.

 

[stkjock]

normal


keep in mind when you let off the go pedal, fuel stops flowing and ignition gets cut, so what does the motor pump in/out more air & less fuel = lean readings

 

[tw0scoops]

13s and 14s normal cruising, below 12 on WOT. Seems like normal readings.

 

[nxhappy]

when you let off the gas it will lean out, which is perfectly fine because there is no load.

when you DON'T want it to run lean is when you are WOT. THEN you should see 11.2-11.8

12 and above would be considered lean while boosting

11 and under would be considered rich

 

[04SNK390HP]

WOT and idle A/F readings are the important ones to monitor. WOT should be between 11.25-12.00. Idle should be somewhere in the range of 14.2-14.9

-Nick

 

[VNMOUS1]

You should average 14.6 at idle and cruise. Short term fuel trims will have stuff constantly moving around but the average at 14.6-14.7

 

[BROK3N-SVT]

Thanks a lot for the input guys. I'll check out the wot reading when I can. I had it out today again but it's just crap on the stock wheels. I'll have big and littles on it in a couple weeks and hopefully a little warmer weather to test things out.

 

[CobraCO]

I am in the Denver area and my air/fuel read between 13.8 and 14.2. Is this the altitude or because of our crappy 91 octane e15 or something else entirely?

 

[moncho]

^ I don't think the AFR is altitude dependent. Hopefully someone else can chime in to confirm. Meanwhile I'd stay out of boost (just in case). What are you using to get the reading?

 

[rotor_powerd]

I am in the Denver area and my air/fuel read between 13.8 and 14.2. Is this the altitude or because of our crappy 91 octane e15 or something else entirely?

Where are you seeing those readings? Idle? Crusing? WOT?

 

[nxhappy]

I am in the Denver area and my air/fuel read between 13.8 and 14.2. Is this the altitude or because of our crappy 91 octane e15 or something else entirely?

If you are idling and or cruising, that is fine.

If you are seeing 14.2 at WOT, then you are running WAY lean.

 

[Red-GT500]

I am in the Denver area and my air/fuel read between 13.8 and 14.2. Is this the altitude or because of our crappy 91 octane e15 or something else entirely?

Sounds like your tuner has it running a little rich. It shouldnt be a huge issue but i would keep an eye on the plugs and change them a little more often to prevent fouling. Rich = Fouled Plugs, Lean = 600lb paper weight under the hood.

 

[rotor_powerd]

Sounds like your tuner has it running a little rich. It shouldnt be a huge issue but i would keep an eye on the plugs and change them a little more often to prevent fouling. Rich = Fouled Plugs, Lean = 600lb paper weight under the hood.

13.8-14.2 isn't "rich" under any condition.

 

[CobraCO]

I get this reading on my aeroforce gauges and logging while idling or cruising. WOT is around 11.8. Don't think I am running rich as plugs have a good color.

Our gas in Colorado (at least the denver area) is 15 percent oxygenated with ethanol which i think is sometimes referred to e15. So I was thinking if the stoich of gas is 14.7, what is the stoich of e15? Turns out it is 13.8 to 14.0! So I think this may be the answer to my question. Is this correct?