EVAP monitor not ready

Tiny
WRENCHERHEAD
  • MEMBER
  • 1996 CHEVROLET CAVALIER
  • 2.2L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 138,000 MILES
I the car listed above three speed automatic transmission (MD125C). It needs to have an emissions test, so I ran my scanner on it as I do every year to verify all sensors are "ready" before getting it smogged. This time the MIL came on, checked the DTC it showed O2 sensor inactivity. I made the repair but out of habit I disconnected the battery before making the repair (as I always do when working in the engine bay) forgetting momentarily that the sensors would return to "not ready" status. Cleared the DTC and performed the drive cycle. All sensors except EVAP came up ready. I researched the I-NET for a specific drive cycle for the EVAP and get different conflicting drive cycle instructions and most are for all the other sensors. Is there a specific realistic cycle I can perform without having to go through the impossible cycle that is requested? It's just not possible to duplicate drive cycle where I live? Trying to drive at steady speed 45-65 for up to 10 minutes and then decal/coast to 20 without braking for another couple of minutes up to 5 or 6 times isn't real world and is dangerous especially on the freeway which is the only place drive 55-65 without chancing a ticket. Tell me there's another way to achieve "ready" status for EVAP that's not risky? Also, I only have two days on my last driving permit to get it smogged. Long story short; I've been working on the car for over a year doing needed R and R and have used up all 6 permits a year allowed (due to little and no time to work care taking both parents 24/7). So it's the 4th quarter with 2 minutes left. ASAP response would be immensely appreciated. Thanks Wrencherhead.
Monday, July 15th, 2019 AT 12:10 PM

3 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Hi,

I hate it when I have nothing but bad news but this is a federally mandated and monitored procedure (which is why you need to have it tested) so there is not a way to "trick" it or force it to run. The only way to force it is to do the drive procedure attached which appears you are already aware of.

Due to you saying you need to pass the Smog test, I assume you are in CA. If so, I would suggest calling the nearest Chevrolet store and ask them where they go to perform this procedure. Unfortunately, when dealing with the Federal gov't (or CA in your case if that is where you are) they are not the easiest to deal with. A lot of shops have installed dyno rollers in CA just for this purpose and they are able to drive anyway needed. It may be worth while to call around and try to find one so you can get this monitor to run in about five minutes.

FYI - The second document is a chart that makes it real easy to understand what is needed. It is a little different then what you laid out but same idea.
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Monday, July 15th, 2019 AT 6:37 PM
Tiny
WRENCHERHEAD
  • MEMBER
  • 34 POSTS
Actually, I'm in Nevada. Last year, the tech at the smog station told me the state allows up to 3 sensors (I'm assuming to a not ready status or fail) before not passing and he didn't specify which ones and I forgot to ask him. But when I got on the DMV site it stated only 2 sensors, not 3 and of course they didn't mention which ones either. However, it was mentioned that a vehicle could or couldn't pass on the EVAP, which tells me nothing. I thought that the EVAP is one of the required sensors to show a ready status for passing. Could you set me straight on that? Now for my next problem. Four days ago, my A/C quit working. From developing a leak on the EVAP tube and I may not find the time to repair it, so how am I going go through the drive cycle without turning it on along with the rear defroster? Is that going to affect the EVAP and leave it not ready? If so, i'm screwed! If I can't repair it in the next 2 days, my last permit for the year expires and won't legally be able to drive it. What do I do?
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Monday, July 15th, 2019 AT 10:39 PM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
The EVAP system is one of the monitoring systems that requires to have the monitor run in order to pass. Even if the monitor has run it could still fail. I am sure you already new this. This monitor is basically looking at the purge valve and its operation. It requires the drive cycle so that it can look at it in all different driving scenarios to see if it is operating.

If your AC is not operating then no it will not run the monitor. You only need the compressor to run because it adds a load to the engine. It doesn't have to blow cold air.

As for what to do, the only thing I can recommend it to take it to a shop at this point and get it fixed so that it passes. They may not run the drive cycle for you but if it were me, I would drive as far out of town as needed to find a road to get this to run.
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Tuesday, July 16th, 2019 AT 1:39 PM

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