Frustrated with emissions monitors - need help
Thread Starter
Pro
Joined: Feb 2006
Posts: 594
Likes: 5
From: O Fallon MO
Frustrated with emissions monitors - need help
Ok, So I am having issues/problems getting 1 of the last 2 monitors to run. I can not get the EVAP or Catalyst to run. I have been going through GM drive cycles, driven 130 miles at 55-60MPH as best I could even in 5th gear and these tests will not run. I have driven almost 1000 miles and have had no luck. The tank is always between 1/4-3/4. I have tried going through the easy to find OBDII drive cycle and tried the service manual route a few time but the driving conditions are a bit tough if you follow the service manual(where do they find these kind of roads?). I have also noticed that they dont get to particular if yuo have a manual either. They dont ever say anything about pull parking brake, depress clutch or all that stuff. So after all this venting I am asking for some helpful hint from anyone 
I do have CATS and no DTC's
Chris
I do have CATS and no DTC's
Chris
Last edited by cwalsh; Aug 11, 2008 at 12:40 PM.
Heel & Toe
Joined: Jun 2008
Posts: 24
Likes: 0
From: Virginia
Besides following the drive cycle, you need to be sure certain enabling criteria are met first. You're fuel level is correct for the evap monitor to run. The intake air and coolant temperatures need to be less than 86 degrees F, and they need to be within 14 degrees of each other before starting the car. I just purchased a 2004 last month and the evap monitor wouldn't complete until I parked it outside at night rather than in a hot garage. This monitor may require two trips (restarts) like the one described. The cat drive cycle, as your probably aware, is more complicated.
Thread Starter
Pro
Joined: Feb 2006
Posts: 594
Likes: 5
From: O Fallon MO
I do park in the warm garage so I may try putting it outside tonight. Supposed to get a bit chilly here tonight. I have been monitoring the fuel level as well. I have been putting about 5-6 gallons in it when it get down to 1/4 so it puts me just around 3/4.
Late Starter, did you do drive cycles when you parked it out side or did you just drive it to work? I only live about 3 miles from there so I would have to take the extreme long way to make a drive cycle work.
Thanks for the reply.
Chris
Late Starter, did you do drive cycles when you parked it out side or did you just drive it to work? I only live about 3 miles from there so I would have to take the extreme long way to make a drive cycle work.
Thanks for the reply.
Chris
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
Do you have your rear O2s turned off? If not, get them tuned out, they just make sure the fronts are working.
I was having the same not ready issues when I used to run my car with headers w/o tuning. After tuning and some proper driving I passed. Never had an issue since putting my cam in back in early 2007.
I was having the same not ready issues when I used to run my car with headers w/o tuning. After tuning and some proper driving I passed. Never had an issue since putting my cam in back in early 2007.
Heel & Toe
Joined: Jun 2008
Posts: 24
Likes: 0
From: Virginia
With the preconditions met and all accessories off, start your engine & let it idle. Accelerate at part throttle to 45 mph and maintain until engine reaches operating temp. Continue at 45 for 3 more minutes. Decelerate to 0 and idle for 2 minutes. Hopefully, this will complete your evap monitor.
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Thread Starter
Pro
Joined: Feb 2006
Posts: 594
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From: O Fallon MO
Safety Car
Joined: Aug 2000
Posts: 4,933
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From: San Rafael CA
I'd bet it is something in your "tune" that is preventing the EVAP and Catalyst tests from running.
Think of it this way .... the "drive cycle" rules are written to make sure that a certain test is performed under the correct (and consistent) conditions ......
For example the Catalyst test requires 5 minutes at 55 to 60 .... that means the cats should have reached their correct and steady state operating temperature when the test occurs.
The EPA wrote the rules so the car is constantly "self testing" ..... they didn't write the rules to prevent testing .... they WANT testing.
I'm betting something in your "tune" is causing the PCM to not start either the cat or EVAP tests .... that's where I'd concentrate my time on this issue.
Think of it this way .... the "drive cycle" rules are written to make sure that a certain test is performed under the correct (and consistent) conditions ......
For example the Catalyst test requires 5 minutes at 55 to 60 .... that means the cats should have reached their correct and steady state operating temperature when the test occurs.
The EPA wrote the rules so the car is constantly "self testing" ..... they didn't write the rules to prevent testing .... they WANT testing.
I'm betting something in your "tune" is causing the PCM to not start either the cat or EVAP tests .... that's where I'd concentrate my time on this issue.