ceo44

Using the wideband, when driving, i am going from 10 pig rich to 20 dangerously lean. At idle, its fine, stays around 13-13.5. The orginal 02's are still in. They only have 9k on them however, i cannot find a simple way to test them. I am not even sure this is what the problem is. The maf is good, everything else is new and i am stumped.

SSpdDmon

iTrader: (10)

How are you reading the AFR? With a scanner or with a display like the LM1 has?

ceo44

I am reading from the gauge. Like you said, its a LC1.

SSpdDmon

iTrader: (10)

So you have an LC1 with an XD1 guage?

When's the last time you calibrated the sensor with the ground wire?

Have you check the grounds?

Are you sure there are no exhaust leaks?

Where is the WBO2 in relation to the NBO2's?

Did you change anything in the tune or is it completely stock?

ceo44

It has been extensively tuned but this seems to be a mystery no one can figure out. My tuner is an awesome tuner and he and I have been left scratching our heads. This is on a forged 347 with ETP heads, custom cam etc pulling 470 rwhp with only mild adjustments on the timing and alot on the injectors because they are 42#.

I have checked, rechecked and checked again for leaks in the intake track and exhaust and it is buttoned up tight. I went as far as doing a smoke test on the exhaust looking for a leak and nothing anywhere.

I thought it may be the maf but it checks out fine, the only thing i have not replaced is the 02's and i am holding off just because of the cost for the heated units and don't want to spend two bills on something that maybe working fine.

foff667

iTrader: (2)

I would assume overlap might be confusing the wideband.

ZL1Killa

iTrader: (17)

why did the injectors need that much changing... mine was install them, change the IFR, -5% on 2 tables and done. ??


also, where is the wideband at? put it up towards the collectors (right after them). i think you said you had it in the x pipe... something ain't right.

what are the specs of the cam? and has the WIDEBAND itself been tuned to be read in the software you are using??
either this is something simple as hell and you aren't thinking of it...or somethin's really f***ed up, lol.

Doc

iTrader: (9)

Have you tried swapping the LSU4 sensor (part of the LC-1)? A hairline crack on the pump cell can give you false readings like you described. Reads fine at stoich/idle, give it any gas and it says you are bone dry lean 20.

brad8266

iTrader: (23)

I would not say 13-13.4 is a good idle either.

NoMoreFWD

iTrader: (1)

I would guess that your LC1 needs to be reset/recalibrated. That is what my pos LC1 does when it loses it settings.

My90Iroc

iTrader: (26)

I think you may need to have your tuner go back through the tune. I have the same symptoms when I turn my maf on. When I'm in SD (maf off) my A/F (using LC1 wideband) stays exactly where I tuned it. Now I'm starting to tune my maf from scratch and I get the exact symptoms you're talking about with the maf on. It almost sounds like the tuner tuned it for idle and WOT on the dyno and didn't do enough for the driving around. I'd check the maf tune.

SSpdDmon

iTrader: (10)

Does it show a 20:1+ AFR while you're giving it gas or only during decel? If it's just during decel, that's probably DFCO kicking in. The other I'd be concerned about is misfires. Misfires will shoot unburnt fuel and oxygen into the exhaust. The sensor will actually read the misfire as a lean condition.