Lean Bank 1 & 2
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Joined: Nov 2004
Posts: 490
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From: Memphis, Tennessee
Lean Bank 1 & 2 Just got done tuning my car on the wideband and I have been throwing codes ever since. We had to dump a whole lot of fuel on the car to get the A/F ratio anywhere close. After about 3.5 hours we got it looking pretty good but now I keep throwing all sorts of SES codes. My last two that I keep throwing are lean bank 1 and lean bank 2. I went ahead and put in brand new 02's but the light keeps coming back on. Do you guys think that we pulled to much fuel or what would be the problem at this point?
One possibility is that the wideband was inaccurate.
Closed loop average look like 0.5V, while wideband
says 14.7? Seems like people have been popping up
with a lot of cal / drift issues recently.
With that many modes, you have to have touched a
lot of tables. Probably want to go back and sanity-
check IFR (for the Accels), VE. You might want to
take the resistor out of the SLP MAF and use a truck
MAF table, the '98-'00 SLP unit adds deliberate lean
error and other changes may just have put the fuel
situation over the top (lean bank code means LTFT
wanted to drift past +25% limit). See which fuel trim
cell is stuck at +25 and that should suggest the bad
actor. Might also recheck for vacuum leaks since you
have a different manifold on, don't know how recent
but perhaps you were just covering up a vacuum
leak by fuel trims all along.
Closed loop average look like 0.5V, while wideband
says 14.7? Seems like people have been popping up
with a lot of cal / drift issues recently.
With that many modes, you have to have touched a
lot of tables. Probably want to go back and sanity-
check IFR (for the Accels), VE. You might want to
take the resistor out of the SLP MAF and use a truck
MAF table, the '98-'00 SLP unit adds deliberate lean
error and other changes may just have put the fuel
situation over the top (lean bank code means LTFT
wanted to drift past +25% limit). See which fuel trim
cell is stuck at +25 and that should suggest the bad
actor. Might also recheck for vacuum leaks since you
have a different manifold on, don't know how recent
but perhaps you were just covering up a vacuum
leak by fuel trims all along.
One possibility is that the wideband was inaccurate.
Closed loop NB average look like 0.5V, while wideband
says 14.7? Seems like people have been popping up
with a lot of cal / drift issues recently.
With that many modes, you have to have touched a
lot of tables. Probably want to go back and sanity-
check IFR (for the Accels), VE. You might want to
take the resistor out of the SLP MAF and use a truck
MAF table, the '98-'00 SLP unit adds deliberate lean
error and other changes may just have put the fuel
situation over the top (lean bank code means LTFT
wanted to drift past +25% limit). See which fuel trim
cell is stuck at +25 and that should suggest the bad
actor. Might also recheck for vacuum leaks since you
have a different manifold on, don't know how recent
but perhaps you were just covering up a vacuum
leak by fuel trims all along.
Closed loop NB average look like 0.5V, while wideband
says 14.7? Seems like people have been popping up
with a lot of cal / drift issues recently.
With that many modes, you have to have touched a
lot of tables. Probably want to go back and sanity-
check IFR (for the Accels), VE. You might want to
take the resistor out of the SLP MAF and use a truck
MAF table, the '98-'00 SLP unit adds deliberate lean
error and other changes may just have put the fuel
situation over the top (lean bank code means LTFT
wanted to drift past +25% limit). See which fuel trim
cell is stuck at +25 and that should suggest the bad
actor. Might also recheck for vacuum leaks since you
have a different manifold on, don't know how recent
but perhaps you were just covering up a vacuum
leak by fuel trims all along.
