I_Need_Land

iTrader: (12)

anyone got any ideas what afr i should see when im on my 2 step?

tomz28

iTrader: (20)

bro think about it. it kills the spark so fuel not getting burned = rich LOL
it will be fine

y2khawk

iTrader: (5)

Wrong

You will read lean while on the 2 step. Think about it, they are Oxygen sensors, not fuel sensors. No combustion = unburnt AIR.

Dean95z28

iTrader: (7)

This guy is correct!!!. You get a lean condition. Mine reads 22 AFR on the 2 step.

HUNTER02SS

iTrader: (24)

+3 on the lean!

cody161

iTrader: (18)

the computer isnt trying to correct it though because you should have the gas pedal crammed in the floorboard and it will be in open loop.

tomz28

iTrader: (20)

wow my bad. its been a mintue but i remenber my car going rich does that mean my car is dick up . but i did have a really rich tune at that time. Now you guys got me thinking, and feeling retarted

now you guys are running autos for the most part right? i still have a M6 if it matters any

boosted LT1

iTrader: (3)

When there is unburnt fuel in exhaust as mentioned the computer will read the O2's and they will indicate a lean condition...BUT there is unburnt fuel in the exhaust so it is ACTUALLY rich.

As the other poster mentioned O2 measure oxygen not fuel....so if you fill the exhaust with pure unburnt fuel the mixture will indicate lean on the O2

That is why exhaust leaks cause the car to run rich computer reads Os and interprits it as a lean condition and adds fuel, sees lean adds fuel...

Fireball

iTrader: (21)

you need to turn off the 2step and read the AFR in that rpm range to get it dialed in...that way when its on the 2step you know its ok...

tomz28

iTrader: (20)

well i get that part i know how o2s work

so do we really care what the wideband reads on the 2 step?

Fireball

iTrader: (21)

you want to know what your AFR is in that area (can't measure it directly...see my previous post) since it will affect spoolup characteristics

I_Need_Land

iTrader: (12)

i have a d1sc procharger, and a 6 spd. driving, that range (1800rpm) is rich like 11.5:1, 2step says 18 or afr at that rpm.

98Z28CobraKiller

iTrader: (17)

Exactly. Once you know that AFR is correct in that area and it starts popping, the AFR will spike lean/rich on your log. I'll post one in a minute.

RsSean

iTrader: (27)

So as long as the AFR is fine off the two step, the car will be ok going lean on the 2 step. I am with OP my AFR is 22.4 on my 2 step at 4k

98Z28CobraKiller

iTrader: (17)

98Z28CobraKiller

iTrader: (17)

Not the best example as there is one lean spike between the 1-2 shift. I hit the limiter and was peddling on my way to it. The one further down towards the end of second is false.