Readying Evap Monitor

I ran the attached drive cycle to the tee at 51 deg F but no dice. I'll keep trying as it keeps cooling (which is taking about 2-3 hours each time) but in the meantime any advice on getting evap ready? I'm allowed one system not ready and I'm trying to reserve that for a troublesome Oxygen Sensor.

 

Mine won’t run it unless the check engine light is off. Is that the case with your truck or is the faulty O2 sensor preventing that?

More detail can be found in the TSB for my vehicle.

 

There are a few differences between the 1GR−FE, which you uploaded and the 2UZ-FE, so I uploaded the 2UZ-FE from the 2005-2006 FSM.

For me personally, the EVAP initially would take me the longest until I followed the Preconditions a little more closely. In particular the take fuel cap off/then back on before starting, temp differences between IAT and ECT, MIL has to be off and 1/2 to 3/4 fuel level.

 

CEL/MIL is off. I believe all preconditions were met. Evap was ready at one point before I had to clear the DTC so I know nothing specific is preventing it. Will just have to try again but atm I'm still waiting on the cooling for the IAT/ECT temp correlation.

The trick here is that P0138 is a two trip code so even if it's flagged while readying catalyst, which I'll do last, it will still only be a pending code with no CEL. I can also get another trip by disconnecting the sensor which will change the code. (I'm currently stranded in a hotel with the family hence the hackery while I wait out a replacement ECU).

Edit: Just to clarify, the 8 hrs is only a recommendation and the important part is the coolant temp right? That's my working assumption since the soaking procedure includes an OR in there.

 

I came across this earlier but ignored it since it's '96-'02 and I'm in an '06. There are significant differences in some of the other drive patterns but I don't note anything different for Evap (other than a note about pending codes).

Hmm, I compared the two and don't see any difference here either.

 

I can't remember exactly but I think the evap readiness on one of my vehicles needed a good flat road I could do 45-55 fairly steady. I needed to barely modulate throttle from the slightest accel/steady to barely slowing and then it set.

 

Yeah, I was hoping due to the similarity there was more info that might shed some light on why it wasn’t working for you.

 

My VWs were the worst about this stuff... Made you jump through flaming hoops while juggling chainsaws to complete a cycle.

 

Make sure you don't go anywhere close to or below 1/4 tank or it won't run.

 

In California it's allowed to have the EVAP to be not ready. Mine wasn't ready cause the battery died completely due to old age and not using the truck that much anymore. So I replaced it and run diagnostics. Did the drive cycle thing early in the morning about 3 AM so minimum traffic. Everything on Ready status except the evap. Passed smog. Check your state smog requirements.

 

Well I was able to get EVAP ready 3 times in about 5 days. The first time the mechanic erased it on accident. The second time I already had the check engine light on (so much for that requirement). The third time was a go and I was able to pass inspection. I was also fighting against sub 40 deg weather most of the time.

I wish I could say that the drive pattern was definitive but I never got the system ready directly through that process. It was always ready the next morning without running the drive cycle again, usually after a casual evening drive. The third time it was ready I didn't even start the vehicle that morning. I just turned the ignition to on to check codes and statuses and it was ready, even though it wasn't the night before, so I took it in.

On a side note the secondary air system wants the same cold soak but it's not nearly as difficult to ready.