When I am cruising my wideband dances from like 14 to 15.5 .. it never stops in one place..

also, while i am slowing down if i just pop it into neutral the wideband will just form two lines like -- -- where the numbers usually are.. then if i give it a lil gas it picks up again.. that normal??

At WOT i'm about 11.8..

just checkin'!

 

Your AFR will never stay constant, and it's completely normal for it to cycle high then low then high etc. That's AFR 101 yo.

Can't help with the -- -- thing, but when I pop mine into neutral it goes rich for a split second. Maybe that's the gauge's way of saying below it's range of AFR?

 

the --- thing should only be when your in gear and it goes into fuel cutoff

 

your car is tuned through the maf it will always go up and down

 

-- means your AFR is either richer than 10.0:1 or leaner than 17.9:1
Mine will do that sometimes under idling conditions as well, but it should correct itself within a couple seconds as it readjusts AFR based on o2 sensor signals

 

sounds like you have a poor tune. a correct tune that guage will hardly have any cross counts. I had one in my turbo firebird and at cruise it ranged 14.6-14.7 and under decel just went lean when the dfco engaged. that was tuned through a maf also. You may get some ranging i suppose but nothing to be concerned with

 

Ever tuned or ridden in a cobalt thats tune with a wb , these a/f dont stay constant.

 

lol no i have not. i am waiting for my block to come back from the machine shop right now so i will probably find that out here soon lol. make sure you have no exhaust leaks. even the smallest ones can cause a ranging like that. but if you did you would probably see leaner numbers under wot. just putting in my 2 cents for whatever it is worth.

 

This guy has it correct.

I have the AEM UEGO Wideband.

All those dashes mean is that your injectors are off. It'll do the same thing if your doing downhill, 40mph, in 3rd and you let off the gas.

Also, as others have said, the dancing is normal, your AFR will never be constant at idle or normal driving conditions.

It should be relatively consistent at WOT, however, because it should be recieving the same AFR the whole time. Mine only fluctuates 1-3 tenths at WOT. If it goes crazy rich out of nowhwere or crazy lean for no reason under WOT you have a problem. Your's is 11.8 which is fine.

 

easy fix, buy a fast wideband or lm1. they are way better i have used all three and have seen the uego be off by almost .5 afr in comparison to the fast while monitoring sanity of both through the wideband on a 5gas analyzer. the uego was the incorrect one. regardless this is the sensor still in my car so i guess i am a hipocrit

monitor ltft's and see how far off they are. if they are close don;t worry at all it they are anything that +-5 then you need a retune. and wot you should lock at 0

 

hey sorry to hijack this but i just bought one and was going to get the o2bung welded in but was wondering how far down the downpipe i should have it installed...thanks

 

jr...your good....all of that is normal. Main thing is to watch for any lean or rich spikes during WOT that change it from your 11.8 (that is what you are tuned for)

 

You guys should read your manuals,
If the injectors were "off" the car would not be running. period.

The -- means the car is out of readable range running lean. EVERY CAR does this under DECEL. Cars do not need much fuel under decel at all. Hell My old turbo cav, i would run to 22:1+ under decel, and idle'd it at 17:1.
The only time AFR's that lean will hurt an engine is under loads, WOT.

 

thx for the replies guys.

 

the injectors dont have to be supplying fuel for the engine to turn over... Im pretty certain the injectors stop supplying fuel when engine braking/coast down if your wideband goes to --

AFRs that lean hurt your emissions..so you should never have those AFRs
by the way, im pretty sure you didnt run over 22:1 AFRs under decel...you probably didnt run any fuel...22:1 is too lean to support combustion. AFRs must fall between 8:1 and 22:1 for combustion to occur

 

Emission's don't mean **** here.

And Yes I did run it that lean, I saw it with my own eyes on the dyno and on the street. There is Theory and there is real life.

if combustion wasn't happening (injectors off) your car would not be running for very long.. Go reflash your car at idle, change the AFR lean enough to get the wideband to do --, i bet ya it still runs, meaning the injectors are on

The wideband does not monitor injectors at all, so it would have no way to know that they were off

 

if the car is in motion, and in gear...you do not need combustion to keep the engine spinning..its the same concept as rolling down a hill and depressing the clutch to start the car..it makes the engine spin. This is what happens when you're engine stops fueling the cylinders on coast down. The car is still in gear, so the engine is still spinning, but there is no combustion occurring.

How did you measure your AFR at those levels btw? Ive never seen a wideband that shows leaner than a 19.9:1 AFR. The AEM for example only shows to 17.9:1 AFR

 

I bet ya it does it with clutch dis engage'd also. and compression will stop an engine without compression in seconds. I know mine does..

My old cavalier ran on Megasquirt, with the wideband wired in it would read just find.

Please explain to me how the Gauge which is separate from the ECM can tell you when the injectors are off??


Either way it doesn't matter, because I really don't give a damn... the thing is, the injectors do not shut off. The -- is past the readable limit of the gauge, that is all..

 

its called deceleration fuel cut. the injectors in the LSJ do turn off on coast down. with no fuel, there is no combustion, therefore there is a lot of o2 coming out of the exhaust, which in turn the wideband o2 sensor reads a lot of oxygen going beyond the wideband's limit explaining the "--" marks. i didnt think it was that difficult to understand

 

running perfectly fine!

 

i didn't think that it was difficult to understand that the -- means its past its readable lean AFR...

OP says it happens when in NEUTRAL, which DFCO should not be on.. SO no the injectors are not off. the car IS just running that lean in neutral.

 

i honestly didnt even read the OP's post. sorry.

 

lazy ass

 

yea i have the same wideband and it does the same things yours do(op) so yeah your fine

 

no thats wrong ur injectors are constantly pulsing other wise how would the engine continue to crank?? a magic cranking monkey on the crankshaft?? the -- -- is when u let off the gas it goes really lean for a split second because air is still being forced in and doesnt get shut off as quick as the gas getting dumped in. so u have that split second delay of where theres more then a 17.9 afr or whatever these things read too.