Evap System Mon

[Rich_007]

2001 5.4
How do I get Evap System Mon to complete.
Says "inc". I need it to say OK so I can pass inspection.

update: Just read the Texas rules and if I read it right, seems you can have one incomplete and still pass with 2001 and newer.
Now I am trying to figure out how long it takes for a pending misfire code to go away or if a pending code flags on an inspection. I get a pending code on cold mornings when I start. Sometimes it lights the light and sometimes not. Only when cold. Once it warms up, I never see any codes.

 

[Ulver]

Not sure about the inspection. They may not pick up the code if it's warmed up.

If you're getting a pending code only on cold starts then I would start with the fuel injectors. Check your ohms before a cold start to make sure you're getting consistent numbers across all injectors, then run a fuel pressure test and look for a drop in PSI. I'm thinking that one of your o-rings may be worn and contracted when cold.. And one you're warmed up the rubber expands and normalizes.

 

[Rich_007]

Thanks Ulver
The pending code cleared itself on the way to the inspection station.
It passed with the Evap System Mon still in incomplete status. He told me that having one incomplete is passable on 2001 (and newer) vehicles.
Sooooooooooo....... at over 280K miles, she lives another year.
I like the old girl, (and I like not having a car payment), but with the age and miles, my pain threshold on repairs is set pretty low.
Rich

 

[hwy73]

That Evap System Monitor takes the longest to set. It may take 200 or so miles depending on how you use the truck. It requires numerous drive cycles, it won't run unless the fuel level in the tank is between 1/4 and 3/4, and the ambient temperature has to be within a certain range. PIA.

 

[tvlunn]

Can a scan tool with bi-directional control force the EVAP system to run when needed?

 

[MesaGuy]

How to Get the EVAP Monitor to Complete:
1. Get you gas tank at 1/2 fuel level. Cannot be more the 3/4, nor less than 1/4. Having it at 1/2 is safest.
So, if you tank is all topped off, you will have to wait until you have used up some gas (don't waste it.) If you go empty, just fill it to 1/2 and go home. CHECK YOUR GAS CAP, and make sure it appears to seal well!
2. Turn off the A/C and the Radio, and the Headlights.
3. Cold soak the vehicle over-night. (e.g. It has to sit for at least 8 hours, and the engine block MUST cool down to a temperature below 80F.) So basically, has to sit overnight.
4. Best to run the test in the EARLY, pre-traffic morning!!!! e.g. Get up at 5am, wait until dawn (so that you can drive without headlights), and THEN and run the test.
5. Start the vehicle, DO NOT turn off the vehicle at ANY time during the test. If you turn it off before completion, then you have to go back to stop 2 (an overnight cold soak....)
6. Let the vehicle idle for 1 minute (warm up a bit).
7. Drive to the freeway.
8. Get on the freeway, and drive between 53MPH and 60MPH. Do NOT go below 53MPH, do NOT go above 60MPH. I find it easiest to drive between 55MPH and 59MPH. In CA, this is slow and hard, hence the early AM start when traffic is light, so that you do not get run over going exactly 55MPH+ in the slow lane. DO NOT USE the cruise control. Manual peddle only, gentle acceleration is best, light touch on peddle, and stay in the speed zone.
9. Drive for at least 10 minutes at 55MPH. I prefer a bit extra, e.g. drive for 12 minutes or more at 55MPH.
10. Exit the freeway, and take note of the time of your first FULL and COMPLETE stop. Time X. DO NOT TURN OFF THE VEHICLE.
11. Continue to Drive in "city" traffic for AT LEAST 20 minutes. City traffic is 0 to 40 MPH. Target driving between 35 and 40 MPH on streets that support that speed. Stop at stop lights/signs. Try to stay stopped for at least 5 second. (So if its close, linger a second or two before the guy behind you honks, so that you can get a 5+ second full stop idle on short lights). You MUST have AT LEAST 4 full and complete stops for 5 seconds or more at idle. I prefer 6 stops in case a few are too short at idle. Usually, it is typically no problem to have 6 stops of at least 5 seconds in "city" driving that lasts 20 minutes.
12. After X+20 minutes, I usually go for X+22 to handle rounding issues between you (a person), and the Evap Monitor (a computer).
13. When "starting" from the stops during the city drive cycle, you want to get up to 35 MPH within 12 seconds each time if you can. But do not go over 40MPH. (Hitting 39 or 40 is just great, but >42 is bad). If you exceed 45, restart your 20 minutes to THAT time, but keep driving... (test will just take longer).
14. When complete with the 10+ minutes of Freeway driving between 53MPH and 60MPH, and the 20+ minutes of city driving between 0 and 40MPH, generally starts, and cruising between 35MPH and 40MPH, with at least 4 stops (6 are better).,
GO HOME, and turn off the vehicle.
15. Recheck your vehicle readiness with your I/M monitor check device. (Or go to an auto-parts store and ask them to check it for you). You do NOT want to reset anything, that will reset the monitors.... and you will have to start over. So DO NOT clear any actual or pending codes! If you have actual codes, the MIL light (check engine light) will be on. If you have pending code, they might go away, depends on what they are.

This will generally cause the Eval Monitor to move from INCOMPLETE to OK status. It is a pain in the butt.
MUST:
1/2 Tank. (Must be between 1/4 and 3/4 for the monitor to run, and being at 1/2 is BEST!)
A/C Off, Radio Off, Lights OFF. (No auxilliiary loads on the alternator, or the monitor will not run.)
MUST be an 8 hour cold soak engine off!
MUST be block temperature below 80F before firing up the engine. 70F is safer.
Speed 53MPH to 59MPH on the freeway. No faster or slower, DO NOT use cruise control!
12+ minutes on Freeway. (Done first, after the 1 min of idle warmup).
22+ minutes on city, 0-40MPH, with 4 stops (6 is better).
THEN you can off the engine, and only then.

 

[gtr09]

How to Get the EVAP Monitor to Complete:
1. Get you gas tank at 1/2 fuel level. Cannot be more the 3/4, nor less than 1/4. Having it at 1/2 is safest.
snip
THEN you can off the engine, and only then.

Just out of curiosity, where did this procedure come from?

 

[MesaGuy]

School of hard knocks. I have a '99 Expedition, 208K on it, in CA, has to get smogged every two years. However, the basics of it are actually described in the '99 Expedition User's Manual (not the Service Manual), in the Emission Controls sub-section, in Maintenance Section. The manual basically only says: 10 minutes Freeway, 20 minutes City driving with 4 required "stops" at full idle.

And I have had trouble a plenty. However, the additional information is based on my hard learnings, and also by much more detailed information from my 2000 Nissan Maxima, which has much better information available, but which was subject to the same CA Emission Requirements as the '99 Expy was. That is where I learned about:
- the 8 hour cold soak requirement. (That is a CARB CA Air Resource Board requirement.)
- the starting with the engine cold (Also a CARB requirement, EVAP is supposed to watch whole warmup.)
- the 1/2 tank requirement. (Nissan mentions this, and I had proven failures on the Expedition where I followed everything in my list, except a FULL tank of gas, and then it didn't work...., requires the 1/2 tank. That is also the CARB requirement from the era.)
- The 55 MPH for freeway was still the technical speed limit in '99/'00, and the tolerance is from the Nissan Manual. (Its possible the Expedition has greater leeway, but I have proven the Nissan does not also through hard knock testing - so I also keep it in the 53-59 zone, no faster, no slower.)
- The Nissan service guide for passing the emissions test specifically mentions the "no load" requirement as well, e.g. No A/C, no lights, no radio, no fan. I had problems with the Expy also until I applied that same rule. Those cause the alternator to kick into a higher output mode, which increases load on the alternator drive belt and engine, and the Evap monitor in the ECM is not calibrated for that load, so it turns off (and won't monitor) when the alternator is in high load mode.
- The extra 2 minutes (12+) freeway is from school of hard knocks. You don't really know when the monitor engages for certain, there is no indicator, even with a tool, so its safer to just run longer. I have tried it before at 9 minutes 45 seconds, and failed.... on the freeway.
- Same for the city driving. The monitor has to sense in your driving that you are achieving "city" driving. e.g. Stops, accelerator from stop (Nissan spec requires achieving 35MPH from dead stop in 10 seconds, e.g. moderate acceleration). All the Nissan requirements are from the CARB requirements, and also from whomever made their ECM for them (either Hitachi or Bosch). They are pretty common.
-I put in the 2 extra City stops because it really does need 4 stops that are compliant (Says that in the Ford user's guide manual). Idle long enough, acceleration back to 35 quick enough (but don't gun it, that might make the Evap Monitor actually fail, which resets you back to INC status, at 0 time).

Best I got. Works reliably for me, as my natural driving pattern is NOTHING like this, so the Evap Monitor is also at INC because I do my own work, and it resets with the battery disconnected (same as for the dealer, they cannot reset it either, its an emission requirement.) Occasionally, I have forgetten the 1/2 Gas Tank rule (to my chagrin, generally wasting an hour of my life running the test and not succeeding, because the tank was full...)

 

[MesaGuy]

One more "rule" that I forget to mention, that is definitely a "rule" (I just forgot because I always use a fixed course at my house that follows this rule, and don't think about it.) For the FREEWAY part, the chunk of freeway has to be as FLAT as you can find. The 55MPH-59MPH is supposed to be applied at low load (e.g. gentle peddle) - and you cannot do that on hilly freeway. (For instance, I have a toll road near me that always pretty empty, but it is NOT suitable because it climbs up and down mountains, and the engine load is not correct for what the Evap Monitor is looking for as its "acceptable input conditions", and the test doesn't work there. So, ALSO, as flat a freeway as you can find, that cannot have "real" traffic on it (e.g. no stop and go). as you have to maintain that 55MPH to 59MPH. If you fall out of that for more than 5 seconds, the conditions are out of spec, and you need to try again tommorow. (After another cold soak overnight... for the engine to cool down. At least 8 hours later.)

 

[MesaGuy]

I really hate the Evap Test. Everyone does.... Its designed to approximate "real" driving, but NO ONE in California drives this way. The only people driving 55MPH (I know, I am there with them when running this program) are the illegal aliens who do not want to get pulled over for any reason, in the right hand lane. The test is actually VERY stressful to run in Speeder-ville CA, because 55MPH can get you killed. Even the Semi's want you running 60MPH, but 59 seems to work with them, and I have found that to work OK. But better to stay closer to 55MPH if you can.
- The Nissan Manual also mentions specially NOT to use the Cruise Control. I don't know if that is because their cruise control may accerate at times harder than the Evap Monitor will allow, or if it is a CARB/Fed. standard requirement, but no Cruise Control.

 

[GlennSullivan]

ODBII drive cycles are a PITA and generally a good way to get into an accident when performing one.

Mesaguy's process is very accurate for Ford vehicles. I found that Chrysler vehicles were much easier.

 

[gtr09]

I really hate the Evap Test. Everyone does.... Its designed to approximate "real" driving, but NO ONE in California drives this way. The only people driving 55MPH (I know, I am there with them when running this program) are the illegal aliens who do not want to get pulled over for any reason, in the right hand lane. The test is actually VERY stressful to run in Speeder-ville CA, because 55MPH can get you killed. Even the Semi's want you running 60MPH, but 59 seems to work with them, and I have found that to work OK. But better to stay closer to 55MPH if you can.
- The Nissan Manual also mentions specially NOT to use the Cruise Control. I don't know if that is because their cruise control may accerate at times harder than the Evap Monitor will allow, or if it is a CARB/Fed. standard requirement, but no Cruise Control.

Wow, every time I think CA or CARB has reached a new level of unsurpassed idiocy I find I'm wrong again. Thanks for sharing all of that info! I just learned about "permanent" codes last week after I swapped new port injectors in and I left one of the fuel rail electrical connectors was not quite plugged in all the way. Started it up, sucker ran on 3 cylinders pretty smooth actually. Realized what happened, took intake off again and plugged the rail in all the way. But I got codes I couldn't remove of course. Did a little reading and all I saw was "drive 200 miles and have to have some overnight cool downs during that". I had no idea it was this absurd. I don't think they'll ever go away unless I make an effort hah.

But, I keep my cars tagged in a state with no emissions, guess I can add 1 more benefit to that.

 

[MesaGuy]

If you have hard codes, then you generally need to put on a OBD-II, and clear them. Of course, when you do that, then all of the emissions state is automatically cleared. e.g., clear any fault code, and all emissions state is set to incomplete monitors. That is CA and Fed. law, so all the vehicles do that. (That is the anti-cheating mechanism). And then, you get the privilege of running the proscribed test program above.

For some (very few) people, just driving a while (usually 2 weeks to a month), will eventually hit each of the sub-components of the emissions monitors. The ones that typically take the longest to get happy are the EVAP monitor, Catalyst (CAT), and Oxygen (O2) sensor. On some vehicles, the EGR and Heated Oxygen Sensor monitors are added to the list.

But for me, its almost always the EVAP monitor. And that one is difficult because it cares about the cold-soak requirement, the 1/2 tank requirement (it measures EVAPORATION Gas fume vacuum condensation system performance, hence the tank has to be 1/2 full, so that there is plenty of room for vapor), and the CAT monitor.
But if following the procedure above, you can crush all the monitors in the one session, they will all set from INC to OK (assuming your care is in correct working order).

I obviously recommend getting an OBD-II monitor. Plenty of them now for your iPhone or Android phone that work wirelessly (usually bluetooth now), or you can get a cheap (but adequate) one from harbor freight. HFT seels a bluetooth (phone use) one for $60, and a low end (codes only) unit for $40. Those are both worth buying and throwing in the trunk..

Units with ABS brake codes (more), SRS (Airbag) codes (more), Live Data capture (more), and "Fix recommendations" (various branding) (more), and Live Data graphing (more+).. I work on my own car, so the +ABS,+SRS(airbag)+LiveData makes sense. The Fix Recomentations basically just give you "English" two sentence explanations (that you can otherwise get using Google on a laptop to lookup Pxxxx code causes and meanings. The internet explanations are generally more complete, but Fix Assist lets you do it in your garage to some extent (or out on the road).

If all you are trying to do is pass emissions, then the $40 units work fine. Amazon sells low end units with OBD-II codes, and print/clear codes options for $20, and even $10. These units all work just fine.

 

[gtr09]

If you have hard codes, then you generally need to put on a OBD-II, and clear them. Of course, when you do that, then all of the emissions state is automatically cleared. e.g., clear any fault code, and all emissions state is set to incomplete monitors.

The hard codes, (actually called Permanent codes) can't be cleared with a scan tool. That's what I meant when I said I could not remove them. Only getting those monitors to complete will do it. I've had code readers for 25 years and I do all of my own work as well. I just haven't worked on a modern enough vehicle that also had one of these permanent codes and I don't have to do emissions testing so by sheer luck I never came across it. On my GTR (2009) some of this crap is just turned off in the ECU so I never dealt with it there, either. I'm just going to ignore them, monitor will complete or it won't but not worth my time to force it.

 

[GlennSullivan]

Also keep in mind that disconnecting, changing or having your battery go dead (such as sports car only driven in summer) will also change the status of these sensors to "not ready" and force a drive cycle test if you need to go through emissions testing near term after that. Right after ODBII arrived on the scene in 1996, I because a huge fan of the Battery Tender products.