So i just got my aem wideband installed lastnight

to my surprise, i did a pull and watched the guage, it went to about 10.9 under wot, which isnt super bad for me not really touching anything in my tune.
But then, when ever im just driving around it bounces from around 14.8-15.4 if i left the gas off the guage reads -.-.- (lol) then goes to like 17.9 back down to 14's.
Idle sitts at around 15

So my question is, is this normal ?
if i get in boost even 0 it stays at 14.7 then goes down until hitting 10.9.
How would i go about tuning my car just when im driving around? cuz 17s is STUPID.
i have not logged my car since i got the guage, and im doing that after work. Gimmie some info

She needs a tune i know that Yay for me lol!

 

you are seeing this because when you first let off the gas the injectors shut off. When they shut off it shows a temp lean condition until they turn back on again thus showing the stoich condition again.

 

closed vs open loop....your car sounds fairly normal as far as AFRs (definitely a tad rich but not crazy)....log the car on various runs, WOT, partial throttle, and see how your car is really running...AFR just tells just part of the picture....

 

not really
Closed loop vs. open loop is more of how the 02 feedback works for correction.
Part throttle is closed loop and WOT is open loop on all other cars i worked with. closed loop allows the 02 to make corrrections to give a stoich mixture.
Open look basically allows you to "hard set" per say the parameters for a set value without the 02 feedback making corrections on its own

 

You guys are all covering the same thing just from different angles.

While cruising, afrs bouncing around 14.7 +- half a point (or more) is normal in 'closed loop' operation. (as stated above).

Getting no reading and then coming back from full lean after letting off the gas is normal for decel fuel cut. This is independent of closed loop operation as my car does this and I have closed loop currently disabled for tuning reasons.

 

Evir....my wideband reads around 10.5 @wot so 10.9 is better also it should read around 14.7 while just idling.

 

to the OP, the afrs you stated all sound fine and within standard operational parameters

 

yup, the behavior of your readings are normal.

your afr at wot isn't.

actually lifting off the throttle should read as lean as possible, your gauge must not read that low.

 

cool, thanks for the replys! 17.9 is the leanest it reads then -.-.- lol.
What should i do to pull more horsepower out?

Now im into the tuning world haha. And my afr is pretty normal. Thats good!
Log time weee

 

If your tuned and seeing that, i would shoot your tuner!!! lol
And if you made those numbers like that, I would praise your tuner. lol

 

Lean it out a little... depending if your tuned or not you can go to 11.3 safely!

 

if his car is on the stock tune that sounds like a factory pig-rich evo to me with bolt ons ---> OP's wot afrs..

 

when you have a boost leak does the w/b get leaner or richer?

 

My IX factory tune was mid 10's.... this is basically normal on any OEM turbocharged/superchanged vehicle...

I've seen it on mazda's, subies, vw's, mits', ford's......... its very hard to damage an engine when you allow the fuel to be extremely rich, hence the condition of why the factory tunes are this way, and hence the reason why a simple tune can give you a decent amount of horsepower w/ no other modications.

As stated above: open loop, closed loop and fuel cut are independent of each other.
and normally running A/F's of 12 flat is perfectly OK, depending on many things under the sun you can even go leaner.... but you don't have to take my word for it.... you will find many many super high 500++++whp graphs by reputable tuners that show 12:1 a/f across the board on these tunes.... most of the times for a safety factor and in high rev range will the fuel drop to mid and low 11's (on gasoline)... and many tuners will tune this way for the sake of there own rep. and you not blowing your engine...

Depending on the dyno, the dyno load and the actual street load on the vehicle can be different, giving different fueling mixtures, and so with any other environmental parameter and fuel you put in the tank..... this is why there are buffer's in tuning both with fuel and ign etc.

Any type of boost leak on a MAF based vehicle should allow a richer mixture, because you are removing air mass that the ECU thought it had giving the adequate fuel, but in reality because of a post MAF leak, it isn't there... hence Air to Fuel ratio.