Today I had to drive to work, I usually take the train. I noticed while scanning at 70 mph my o2’s went flat and noticed I was commanding 16.40 AFR. My wideband was not installed at the time but this has happened before and my wide band was showing 16.00.
Is this DFCO ? O2 Sensor going bad? I can’t figure out where this 16.40 is coming from. Any thoughts?
Thanks in advance. Happy Friday!!
Last edited by GTPNoga; 04-18-2008 at 04:24 PM.
2004 GTP: 3.8L SC, XP CAM, 85MM Maf, 105# Springs, 3.3" Pulley, Autolite 103's K&N CAI, 3" Downpipe: TOG Headers, #39 Cobra Injectors, ZZP Crate motor with CNC Ported Heads, NGK AFX Wideband
Have you made any changes to the DFCO tables? I had changed mine just a bit and the same thing was happening for the last couple of weeks. Put the tables back to stock and problem is now gone.
Nope didn't touch the DFCO tables.
2004 GTP: 3.8L SC, XP CAM, 85MM Maf, 105# Springs, 3.3" Pulley, Autolite 103's K&N CAI, 3" Downpipe: TOG Headers, #39 Cobra Injectors, ZZP Crate motor with CNC Ported Heads, NGK AFX Wideband
You learn something new every day!!
Found this in another thread on the V8 side.
UPDATE: I found out what I think is enabling Lean Cruise.
I started with the stock map and changed only the injector size plus disabled the DTCs for the Bank 2 sensors (I removed one to put a wideband in it's place).
Sure enough, with just those two changes, the Lean Cruise still came out. I think changed all of the 02 Bank 2 DTCs from "3 - No Error" to "2 - No MIL", and reflash.
Now it does not go into Lean Cruise. Weird.
Somehow setting the 2nd O2s to "No Error" allows Lean Cruise to get enabled?
Any ideas Bill?
Cheers!
Jeff
2004 GTP: 3.8L SC, XP CAM, 85MM Maf, 105# Springs, 3.3" Pulley, Autolite 103's K&N CAI, 3" Downpipe: TOG Headers, #39 Cobra Injectors, ZZP Crate motor with CNC Ported Heads, NGK AFX Wideband
Ask the obvious question... any chance of exhaust leaks?
'99 Black GTP Sedan
3.4-2.6" PB Quick Change pulleys, Custom CAI, XP Cam, N* TB, LQ4 MAF, SLP headers, 42.5# Injectors, 180/195* thermostat.
13.501 @ 103.392 on 91 (2.4 60-foot).
13.82 @ 105.28 on 87 octane! (2.42 60-foot).
263kph top end as shown on the GPS.
All this and 39MPG to boot. What more can a man ask for?
* Just another enthusiastic amateur tuner! *
No exhaust leaks I checked all my flanges and connections just to be on the safe side.
Since I don’t have a rear O2 I set the rear O2 codes to 3 No Reporting. I guess that enables Lean Cruise. I set my rear O2 sensors to 2 No Mil Light and it fixed the issue. So far no more 16.40 AFR.
2004 GTP: 3.8L SC, XP CAM, 85MM Maf, 105# Springs, 3.3" Pulley, Autolite 103's K&N CAI, 3" Downpipe: TOG Headers, #39 Cobra Injectors, ZZP Crate motor with CNC Ported Heads, NGK AFX Wideband
This should go into the "Problem/Solution" thread...or "sticky" it I think.
I definately am weak on 2004+ GPs, but I am like 90% sure that the 98-03s don't have a lean cruise mode at all... I wish it would, maybe it could take me over the 40 MPG barrier.
If I have a spare weekend, I may play with that. Oh, I also don't have a rear O2, haven't had one in over a year, and not noted O2s that would suggest a lean cruise condition. I put in a WB recently, so that will be something for me to watch for... I could be totally off (but don't think so).
'99 Black GTP Sedan
3.4-2.6" PB Quick Change pulleys, Custom CAI, XP Cam, N* TB, LQ4 MAF, SLP headers, 42.5# Injectors, 180/195* thermostat.
13.501 @ 103.392 on 91 (2.4 60-foot).
13.82 @ 105.28 on 87 octane! (2.42 60-foot).
263kph top end as shown on the GPS.
All this and 39MPG to boot. What more can a man ask for?
* Just another enthusiastic amateur tuner! *
I guess the Lean Cruise tables are not mapped yet but they are in the PCM somewhere. I guess the right combination could enable lean cruise. Now that brings up a good point I am NOT seeing any KR so during cruise is it beneficial to have lean cruise? hmmm
2004 GTP: 3.8L SC, XP CAM, 85MM Maf, 105# Springs, 3.3" Pulley, Autolite 103's K&N CAI, 3" Downpipe: TOG Headers, #39 Cobra Injectors, ZZP Crate motor with CNC Ported Heads, NGK AFX Wideband
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