Computer Diagnostics and Tuning Technical discussion on diagnostics and programming of the F-body computers

Rejected PCM on emissions test

Thread Tools
 
Search this Thread
 
Old Sep 9, 2002 | 06:12 PM
  #1  
d-cyco-1's Avatar
Thread Starter
Registered User
 
Joined: Nov 2000
Posts: 42
From: Bolingbrook IL , USA
Post Rejected PCM on emissions test

Took emissions test last week and I failed the OBD II part because the PCM was rejected. Does anyone know what that means, and or what there computer is looking for? I have LT! edit and there were no codes and the ses light was off. Any help would be appreciated.
Chris
Old Sep 9, 2002 | 06:56 PM
  #2  
CanadianZ's Avatar
Registered User
 
Joined: Aug 2000
Posts: 78
From: Nanaimo, BC. Canada
Post

I don't know who does your testing there but I would find another place to go. I have heard of a lot of people in California that can't pass the visual because of LT's moving the original cat location but still getting passed because they pass the sniffer.

If there are independant shops there that do the tests see if one of them will just let you pass the ECM part as long as you pass the sniffer.

CanadianZ
Old Sep 9, 2002 | 07:21 PM
  #3  
ROCKN SS's Avatar
Registered User
 
Joined: Sep 1998
Posts: 167
From: Indianapolis, In, USA
Post

Do you have LT1 Edit for the OBDII computer or did you swap to an OBDI computer. If you swapped that's the problem.
Old Sep 9, 2002 | 08:01 PM
  #4  
d-cyco-1's Avatar
Thread Starter
Registered User
 
Joined: Nov 2000
Posts: 42
From: Bolingbrook IL , USA
Post

I have Lt1 edit for OBD II. The car is failing on hydo carbons with a leverl of .90 with a max allowable of .60. Here in IL on OBDII cars, if you pass the computer check then u do not have to take the sniffer test. That is why i wounder wht it was rejected. The 2 previous test the PCM was not rejected. The only thing i have turned of for the emissions test is the code P0300. LEt me know if you have any questions.
Old Sep 10, 2002 | 04:11 PM
  #5  
Rlhay2's Avatar
Registered User
 
Joined: Aug 1999
Posts: 15
From: garland tx
Post

<font face="Verdana, Arial" size="2">Originally posted by d-cyco-1:
The 2 previous test the PCM was not rejected. </font>
Have you recently disconnected your battery? If so, you reset your OBDII diagnostic indicators which are only reset after a certain number of OBDII drive cycles are completed. More info here: http://www.obdii.com/drivecycle.html
--
Ronnie
Old Jul 19, 2003 | 08:16 PM
  #6  
Jon A's Avatar
Registered User
 
Joined: Dec 1969
Posts: 482
From: Mukilteo, WA
Here's a question for you guys:

Does the OBDII computer scan test make it harder or easier to pass emissions with a big cam?

Here's a copy of my last test (stock engine):

http://www.jonaadland.com/NewPics2/2...sionsSmall.JPG

That's it. I could have been spewing all sorts of raw gas and noxious fumes out the pipes--as long as their computer says my computer is OK I pass.

Does this mean you can run a bigger cam if you stick with your OBDII computer as long as you can make your computer pass their test with LT1 edit?

It sounds too good to be true. What am I missing?

Last edited by Jon A; Jul 21, 2003 at 01:59 PM.
Old Jul 19, 2003 | 10:14 PM
  #7  
96TurboTA's Avatar
Registered User
 
Joined: May 2003
Posts: 647
From: Brockton, Ma
Did you turn off the Misfire test? If so, that may have caused you to fail. Just a thought
Old Jul 21, 2003 | 09:17 PM
  #8  
d-cyco-1's Avatar
Thread Starter
Registered User
 
Joined: Nov 2000
Posts: 42
From: Bolingbrook IL , USA
I have turned off the codes to the egr and the misfire in both of the tables. Does turnining of the tests in lt-1 edit cause your computer to fail, and is it a fact that you will fail the computer scan/rejected pcm if these testes are turned off? If it is true I would be willing to try it. For now I got around the emissons testing by having show car insurance put on the car. Any Details on what the emisson test is looking when your computer is scanned would be helpful.
Chris
Old Jul 22, 2003 | 01:25 PM
  #9  
cd520's Avatar
Registered User
 
Joined: Nov 2002
Posts: 47
From: WV
I'm by no means an expert on this but I would turn those functions back on. If they hook to your computer I'm sure having EGR off is seen immediately being a function of emmisions.
Old Jul 22, 2003 | 03:23 PM
  #10  
SMOKNZ's Avatar
Registered User
 
Joined: Apr 1999
Posts: 1,178
From: Cleveland, WI
Don't know about IL but in WI I failed my PCM test because i had a code disabled. The emissions place specifically asked if I had anything disabled in the PCM which I had the crank position sensor disabled for the dual roller tiing chain/electric waterpump conversion. Somehow they can detect that. You can change anything you want to make the car run cleaner, but you can't disable any codes.

Bill
Old Jul 22, 2003 | 03:30 PM
  #11  
96TurboTA's Avatar
Registered User
 
Joined: May 2003
Posts: 647
From: Brockton, Ma
I'm running a XE224/236/114LSA in my 383 with all of the tests, except rear O2s, running and haven't seen any misfire codes.
Old Jul 23, 2003 | 07:38 PM
  #12  
d-cyco-1's Avatar
Thread Starter
Registered User
 
Joined: Nov 2000
Posts: 42
From: Bolingbrook IL , USA
Let me get this straight. Do you need to have the the tests on and nil light off for the computer pass, or both, the test and the mil light to pass. If you enable the mil light you cannot get around emissions if your computer finds something wrong like a misfire or egr valve problem. Does this sound right?

Chris
Old Jul 25, 2003 | 12:08 AM
  #13  
97Whitez28's Avatar
Registered User
 
Joined: Mar 2002
Posts: 153
From: Homer Glen, IL, USA
If you just turn off the different tests in the PCM the test software will read the PCM as Not Ready.

What you need to do is turn everything back on....In IL you are allowed to fail one or two critical areas...These include: EGR,CATS,AIR, MIL and I believe there are two more that I can't think off right off the top of my head.

You are getting code P0300 because there is not enough exhuast gas getting back into the system. I assume you are running either !Cats or have set of headers. What you will have to do is restrict the exhaust a little bit so the gasses can get back into the EGR valve. Don't ask me how to do this, I have no idea??!?

If you turned off the MIL light I think that it automatically fails you...I'm not to sure on it.....Call one of the testing stations and see if they will give you any information.


I put my car back together the day after I got my emissions done so I have just under 2 years until I have to go again. I didn't throw any codes when it was first started w/o a tune and I am
!cats, !air...I just used a set of 02 sims and it was fine.....

I would try turning everything back on and doing it again.....you get to try more than once before they suspend your plates....

And to answer the other question, as long as the emissons people goto just the PCM test you will be able to do many things and stay emissons legal...Including running very large cams....
Old Jul 25, 2003 | 07:52 PM
  #14  
d-cyco-1's Avatar
Thread Starter
Registered User
 
Joined: Nov 2000
Posts: 42
From: Bolingbrook IL , USA
I understand what you are saying by turning those functions backon, but if I do that then I garantee you that I will get the engine light. This is one of the reasons why I got the software, to get around engine lights. The way it is looking is that there is no way to pass emissions. You either fail because the car sees something wrong (code p0300 for ex.) because of mods, or you fail because the computer does not have the functions enabled. I wish someone new exactly what the emissions place was looking for.

Chris
Old Jul 26, 2003 | 08:15 PM
  #15  
wrencher's Avatar
Registered User
 
Joined: Feb 2003
Posts: 126
From: Chicago Illinois
You disabled the radom missfire code it shuts of the missfire readiness test.
They put your car on the dyno & ran the IM-240 right?
(they are doing this till the end of the year for OBD-II cars)
Then you have to now pass the IM-240 dyno test.
Now that it failed the IM-240 you have to pass it.
Does you car have the stock cat?
If it does/or does not you may need to replace them & get tested.
This is my suggestion, Do the cats ,go to station on a cooler day/low humiity.
You can go into the office w/ your failure sheet & purchase a voucher for a test that does'nt count against you>$20.
Go to the lane & tell the "inspector" you want a pre-condition.
They will run the car on the dyno then test it.
If it passes then take it back around & do the exact same.
If your car is a M-6 car ask in the office whom the best driver is it makes a huge differance.
I deal with them all the time & it's not fun, but not knowing your exact set-up this is basic. Good luck!!!



All times are GMT -5. The time now is 06:40 AM.