Aside from a toasted oxygen sensor, that is.

I'm using Diacom to get all these values, not the gauges, so I'm seeing the same information the ECM sees.

I know the car is running lean, Vader correctly pointed out the issue with my "temporary" breather filter (hey, it beats an open hole in the valve cover) and the few times I was able to get the car in closed loop the block learns jumped way up. I didn't really get to see how far because it dropped right back out.

Give me a rundown here as to what's necessary for the car to go into closed loop. I was under the impression it was:

1) Running for X minutes
2) O2 sensor warmed up
3) Coolant temp above Y degrees

Coolant temperature seems to be a steady 180-190 (as observed by the ECM via the CTS) once the car is warmed up; I even shut off the fan and let it go up to 200 with no improvement.

O2 sensor is not cycling hardly at all when the car is in open loop. It read .415 when the car was ice cold (thought it was supposed to read .450, that's what MY car reads), then cycled and went int to closed loop around 150 on the CTS, then dropped back out and read .330mv for most of the rest of the time. It would occasionally go back into closed loop for a second or two, but wouldn't stay. The only known problem at this point is the lean condition, but I've never seen a lean condition drop the ECM out of closed loop before, so I'm confused.

We definitely let the car run long enough, but I was too busy when the car was moving to notice if the car was in open loop (I was watching the knock sensor counts).

I'm tempted to replace the O2 sensor while I'm doing plugs and wires since I know the CTS is good and I can't think of anything else to do. I'm kind of at a loss with this new-fangled EFI cars if they won't stay in closed loop long enough for me to figure out what's wrong.

 

Were you driving the car, or just letting it idle? It's not uncommon for the ECM to stay in open loop during prolonged idling. A dirty O2 sensor would make that problem worse. If you haven't, try driving the car while monitoring the scanner, and maybe change the O2 sensor. The ECM should go into closed loop after 156 degrees(I think that's the number, or pretty close to that). My car had a similar issue where it wouldn't go into closed loop at all. It was the O2 sensor circuit in the ECM that was broken somewhere on the circuit board creating an open circuit. The SES light would come on during highway driving indicating a lean condition. Hope this info helps a little.

 

Both, but I was unable to monitor the scan tool for open/closed loop while driving. I'm thinking that's the reason I heard audible knock, however--the timing was less than 5 degrees to advanced, so the ECM should have been able to pull timing if it was in closed loop.

I wasn't just sitting at idle though, I was bringing it up to 1500 and 2000 rpm to check various things. It would only go into closed loop when it felt like it, maybe once or twice the whole night.

 

I see you have a scanner but there is no mention of any trouble codes??????

A code 44 lean could cause you to be in "limp home mode" instead of going closed loop.

A bad Coolant Temp Sensor can prevent TCC lockup and keep you from going closed loop. Code 15 I believe.

~~~~~~~~~~~~~~~~~~~~
Red 86 T/A 5.0 TPI (LB9/WS6)
~HyperTech Cap/Coil/Rotor/AFPR
~Derale Adjustable Fan Switch ~ 170° Stat
~Flow Matched Injectors ~ K & N Air Filter
~Ported Plenum ~ Pirelli 245/50/16
~SLP TB Airfoil ~ All Else Stock

 

No, no codes. It never stayed in closed loop long enough to throw one.

Limp mode is STILL closed loop on my CCC, even though there will be codes present.

We did plugs and wires on it last night and found a badly burned plug wire on the driver's side:



That seemed to smooth it out a little. I didn't have time to scan it again.