96 LT4 failed AZ emissions. HELP!!
Thread Starter
Burning Brakes
Joined: Apr 2000
Posts: 980
Likes: 2
From: Chandler AZ
96 LT4 failed AZ emissions. HELP!!
I am the proud owner of a 96 LT4CE. I recently took it to AZ emissions and they gave me bad news. I was told the computer told them it hadn't completed the test on the catalyst AND o2 sensors. (this is confirmed by my scan tool.) They had to run it on the rollers. It failed miserably. I thought all they did was connect to the DLC and if there are no codes it passes. Please help if you can. I have to park it until I can get it tagged.
Vince
Vince
Thread Starter
Burning Brakes
Joined: Apr 2000
Posts: 980
Likes: 2
From: Chandler AZ
It has about 85000 on it. I don't think the alcohol will do the trick. They should just test by hooking up to the computer and looking for error codes. They shouldn't have to put it on the rollers.
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Originally Posted by VAHROOM
It has about 85000 on it. I don't think the alcohol will do the trick. They should just test by hooking up to the computer and looking for error codes. They shouldn't have to put it on the rollers.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,008
From: Texas
Originally Posted by VAHROOM
It has about 85000 on it. I don't think the alcohol will do the trick. They should just test by hooking up to the computer and looking for error codes. They shouldn't have to put it on the rollers.
Unless someone has reprogrammed the PCM, it's hard to believe the SES light isn't on given the tests it failed.
Which o2 sensors failed? There are four of them on '96s. The two in front of the cats are used for fuel control. The two aft of the cats are used to verify cat operation.
Safety Car
Joined: May 2002
Posts: 4,010
Likes: 26
From: Somewhere nowhere
NY state just started the OBD2 plug in test. If it fails, I believe it fails, no 2nd chance for rollers.
all 1995 and older still get dynoed.
but that doesn't help you much, sorry. I wish I knew more about it...
all 1995 and older still get dynoed.
but that doesn't help you much, sorry. I wish I knew more about it...
Thread Starter
Burning Brakes
Joined: Apr 2000
Posts: 980
Likes: 2
From: Chandler AZ
Originally Posted by Zix
What's been done to the car and/or the computer? My LT4 with long tubes and no cats passed the AZ plug-in test without any issues.
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Intermediate
Joined: Aug 2004
Posts: 49
Likes: 1
From: Crown Point IN
Same problem here, my vette isnt as kick butt as yours but I had to give in and take mine to a dealer for diagnostics, they said the 02 sensors had failed causing the converters to go. This is for a 92 LT1. Dealer quoted me 1300, I did it myself for 250. Good luck, I know how depressing it is to not have it on the road. Apparently I didnt read all the previous posts and didnt know you had modified all those components. Ill leave this up for the heck of it.
Last edited by jdawgC4; Sep 30, 2004 at 12:03 AM. Reason: didnt know it was modified exhaust
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Originally Posted by bogus
Repeat after me: "Return exhaust to stock condition, then retest."
Thread Starter
Burning Brakes
Joined: Apr 2000
Posts: 980
Likes: 2
From: Chandler AZ
Originally Posted by Zix
No need, I passed without cats...he should be able to do the same. My rear O2 sensors where programmed out of the computer by Ed Wright...they read a constant .450. I'm not using O2 sims. Who did you talk to at EM? Talk to Trevor if you can, tell him what's going on. He knows my car very (black and silver LT4) well and should be able to help you out.
vince
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Originally Posted by VAHROOM
I don't know who I spoke with at EM. I think I was told Ed did mine also. I do have a sticker on the computer that says EM LT4.30.bin. Is this the same as yours? My rear O2's read .400 acording to my scan tool but I still see that the computer has the Catalys Monitoring showing as not complete. Thanks I will talk to Trevor today. BTW which inspection station did you go to? I may have just visited the wrong one. Thanks for the help.
vince
vince
Scottsdale
7339 E. Paradise Ln.
Scottsdale
85260
I had my computer reprogrammed before I moved to AZ, so I'm sure I have a different config than yours...plus mine is still a 350, not a 383. I have a scan tool, and there are no codes being stored at all so there must be a small problem somewhere. Talk to Trevor, and then talk to someone at Ed Wrights place...they should be able to hlpe out as well.
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Originally Posted by VAHROOM
Convertible with a roll bar. CE and other than the bar, stock looking.
Melting Slicks
Joined: Nov 2002
Posts: 2,471
Likes: 2
From: 1993 Quasar Blue 'vert Scottsdale AZ
Does the car have to be a certain year before they hook you up to a computer? Mine's a '93 and had mine tested just off Greenfield Rd. in Mesa. They just put in on the rollers and it easily passed. Since then, Trevor installed a new exhaust system for me and hopefully it will pass next time.
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Originally Posted by Lichen
Does the car have to be a certain year before they hook you up to a computer? Mine's a '93 and had mine tested just off Greenfield Rd. in Mesa. They just put in on the rollers and it easily passed. Since then, Trevor installed a new exhaust system for me and hopefully it will pass next time.
Thread Starter
Burning Brakes
Joined: Apr 2000
Posts: 980
Likes: 2
From: Chandler AZ
OK just for the sake of discussion.
When I get the O2's working properly, and the computer is happy, how long does the computer take to complete its catalyst montoring. Is it by mileage or run time? I can keep checking it with my scan tool but I am just curious.