Emission Recall
8th Gear
Joined: May 2015
Posts: 8
Likes: 4
yup
That's good to hear!
However, one thing that the Corvette engineer mentioned is that the ECM would be programmed to lean air fuel at low rpm. The computer is programed to maintain 14.68 air fuel ratio at cruise or part throttle. Leaning out that value would probably do more harm to the catalytic converters and performance, especially with the ethanol in todays gas. From what you described with your car, I bet they leaned out open loop or wide open throttle values. This would increase performance, especially because the factory tune commands a rich 11.25 to 11.75 air fuel ratio. I would love to compare the new vs. original tune. When I get the recall done I will make a copy of the tune to compare. It will be interesting to see what GM actually did to the ECM.
The other reason that your car runs better just might be that your cats were starting to get clogged.
Enjoy your car!
However, one thing that the Corvette engineer mentioned is that the ECM would be programmed to lean air fuel at low rpm. The computer is programed to maintain 14.68 air fuel ratio at cruise or part throttle. Leaning out that value would probably do more harm to the catalytic converters and performance, especially with the ethanol in todays gas. From what you described with your car, I bet they leaned out open loop or wide open throttle values. This would increase performance, especially because the factory tune commands a rich 11.25 to 11.75 air fuel ratio. I would love to compare the new vs. original tune. When I get the recall done I will make a copy of the tune to compare. It will be interesting to see what GM actually did to the ECM.
The other reason that your car runs better just might be that your cats were starting to get clogged.
Enjoy your car!
Instructor
Joined: Jul 2004
Posts: 248
Likes: 40
From: Carlsbad CA
That's good to hear!
However, one thing that the Corvette engineer mentioned is that the ECM would be programmed to lean air fuel at low rpm. The computer is programed to maintain 14.68 air fuel ratio at cruise or part throttle. Leaning out that value would probably do more harm to the catalytic converters and performance, especially with the ethanol in todays gas. From what you described with your car, I bet they leaned out open loop or wide open throttle values. This would increase performance, especially because the factory tune commands a rich 11.25 to 11.75 air fuel ratio. I would love to compare the new vs. original tune. When I get the recall done I will make a copy of the tune to compare. It will be interesting to see what GM actually did to the ECM.
The other reason that your car runs better just might be that your cats were starting to get clogged.
Enjoy your car!
However, one thing that the Corvette engineer mentioned is that the ECM would be programmed to lean air fuel at low rpm. The computer is programed to maintain 14.68 air fuel ratio at cruise or part throttle. Leaning out that value would probably do more harm to the catalytic converters and performance, especially with the ethanol in todays gas. From what you described with your car, I bet they leaned out open loop or wide open throttle values. This would increase performance, especially because the factory tune commands a rich 11.25 to 11.75 air fuel ratio. I would love to compare the new vs. original tune. When I get the recall done I will make a copy of the tune to compare. It will be interesting to see what GM actually did to the ECM.
The other reason that your car runs better just might be that your cats were starting to get clogged.
Enjoy your car!
Heel & Toe
Joined: Jul 2009
Posts: 20
Likes: 2
From: NY NY
Also see the following thread
Maybe someone can merge all threads referring to recall 14523.
For now also see the following thread:
https://www.corvetteforum.com/forums...ew-recall.html
For now also see the following thread:
https://www.corvetteforum.com/forums...ew-recall.html
Safety Car
Joined: Feb 2007
Posts: 4,684
Likes: 107
From: Opelika Alabama
that's brillant! GM found that they had a problem with the cats and had tuned the car to those cats and now they want to correct the problem and fix the car free, keep driving around on plugged/restrictive cats. have fun, if you have a "custom tune" I would TELL them not to reflash, but I would definitly get free new cats and then see my tuner, to those who have stock they DID NOT SELL A DETUNED MODEL FOR CA. THEY ARE NOT GOING TO TAKE ANYTHING AWAY JUST THINK!!!! IT MIGHT GET BETTER!!!!! but watch out for the black drones that will follow you around now.
Heel & Toe
Joined: Jul 2009
Posts: 20
Likes: 2
From: NY NY
It's all or nothing on the 14523 recall. They won't let you cherry pick what portions of recall to complete, & once you have it done there's no going back. See my prior post on what the car runs like after the recall was done.
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Melting Slicks
Joined: Aug 2005
Posts: 2,821
Likes: 204
From: Lincoln CA
Heel & Toe
Joined: Oct 2008
Posts: 23
Likes: 0
Do not do this if you like the sound of you dual mode exhaust NPP
I got the notice and nobody could tell me what was going to happen if I did it. So I weaseled my way into General Motors corporate and spoke to one of the top Corvette engineers. He told me that the catalytic converters are better than the stock units in that they flow more freely. He also said they will never plug up. Which is why the old ones were recalled. So if you leave the old ones on you are actually D tuning the car because the old ones are plugging up. get the recall done. In terms of the reprogramming of the engine control module he said all it does is lean out the air/fuel mixture at low rpm. There will be no performance change whatsoever. However mileage will increase in the city cycle. Now that I have had the recall done I can tell you the car is actually better performing than prior to the recall especially at low rpm. I was very wary of having this work done because fooling with the emissions is problematic at best. But I am very glad I had it done for two reasons the first reason is because the car sounds better the second reason is because the car performs better and I am actually seeing increased mileage as promised. I encourage you all to make your own decision however take this post as an indicator that the recall when performed correctly actually improves the vehicle in many ways. I hope this post helps you.
Intermediate
Joined: Jul 2015
Posts: 28
Likes: 2
Racer
Joined: Apr 2015
Posts: 430
Likes: 32
I got the notice and nobody could tell me what was going to happen if I did it. So I weaseled my way into General Motors corporate and spoke to one of the top Corvette engineers. He told me that the catalytic converters are better than the stock units in that they flow more freely. He also said they will never plug up. Which is why the old ones were recalled. So if you leave the old ones on you are actually D tuning the car because the old ones are plugging up. get the recall done. In terms of the reprogramming of the engine control module he said all it does is lean out the air/fuel mixture at low rpm. There will be no performance change whatsoever. However mileage will increase in the city cycle. Now that I have had the recall done I can tell you the car is actually better performing than prior to the recall especially at low rpm. I was very wary of having this work done because fooling with the emissions is problematic at best. But I am very glad I had it done for two reasons the first reason is because the car sounds better the second reason is because the car performs better and I am actually seeing increased mileage as promised. I encourage you all to make your own decision however take this post as an indicator that the recall when performed correctly actually improves the vehicle in many ways. I hope this post helps you.
I mean no offense here although it likely comes across that way but...
What exactly did you do? You went to GM HQ and told the receptionist that you were there to speak to one of the top Corvette engineers? I commend you for contributing to the thread certainly, just curious for more details.
Heel & Toe
Joined: Dec 2014
Posts: 24
Likes: 0
From: Toms River New Jersey
*** Received letter today 9-15-15 for my 2008 3LT Z51 with 44,460 miles with B&B Fusion exhaust in New Jersey.
Made earliest appointment with dealer for 9-29-15 @ 7:30am. Will let you know when it is done.
Recall number - N140523
GM Program #:
N140523
Date Issued:
Mar 30, 2015
Program Title:
EMISSION COMPLIANCE
--------------------------------------------------------------------------------
Program Status: INCOMPLETE
Made earliest appointment with dealer for 9-29-15 @ 7:30am. Will let you know when it is done.
Recall number - N140523
GM Program #:
N140523
Date Issued:
Mar 30, 2015
Program Title:
EMISSION COMPLIANCE
--------------------------------------------------------------------------------
Program Status: INCOMPLETE
Last edited by Whistler60; Sep 15, 2015 at 03:59 PM. Reason: Recall Number N140523
Safety Car
Joined: Nov 2007
Posts: 4,436
Likes: 875
From: Bay Area CA
*** Received letter today 9-15-15 for my 2008 3LT Z51 with 44,460 miles with B&B Fusion exhaust in New Jersey.
Made earliest appointment with dealer for 9-29-15 @ 7:30am. Will let you know when it is done.
Recall number - N140523
GM Program #:
N140523
Date Issued:
Mar 30, 2015
Program Title:
EMISSION COMPLIANCE
--------------------------------------------------------------------------------
Program Status: INCOMPLETE
Made earliest appointment with dealer for 9-29-15 @ 7:30am. Will let you know when it is done.
Recall number - N140523
GM Program #:
N140523
Date Issued:
Mar 30, 2015
Program Title:
EMISSION COMPLIANCE
--------------------------------------------------------------------------------
Program Status: INCOMPLETE
Melting Slicks
Joined: Sep 2008
Posts: 2,360
Likes: 59
From: San Jose California
Just got my letter today, it really sucks for me since I have a full 3" exhaust. (Manifolds, cats, and borla ATAK)
Mine is an 08', just hoping they don't add the extra cats on the 08'. This way I can just have my X-pipe modded.
So, please let us know if any extra cats are added.
Thanks,
DJ
Mine is an 08', just hoping they don't add the extra cats on the 08'. This way I can just have my X-pipe modded.
So, please let us know if any extra cats are added.
Thanks,
DJ
Race Director
Joined: Oct 2005
Posts: 14,999
Likes: 200
From: Bay Area Ca.
Confirmed that the 2008 gets a new mid pipe because it does have the smaller cats added, making 4 now just like the 2009 recall. Now all the LS3's have 4 cats in the C6's.
I just ordered mine.
I just ordered mine.
Instructor
Joined: Nov 2007
Posts: 137
Likes: 0
From: Massachusetts
I am in Mass and got the recall, my understanding is that Mass adheres to the California rules.
Does anyone know if a car will still pass inspection if this recall is not completed? I wonder if emission related recalls require manufacturers to submit a list of VINs to the state inspection agency, and if they update the list when a car has the recall done.
I have to assume that states who use CARB will fail your inspection for emission recalls that are not completed...unfortunately..
Does anyone know if a car will still pass inspection if this recall is not completed? I wonder if emission related recalls require manufacturers to submit a list of VINs to the state inspection agency, and if they update the list when a car has the recall done.
I have to assume that states who use CARB will fail your inspection for emission recalls that are not completed...unfortunately..
Race Director
Joined: Oct 2005
Posts: 14,999
Likes: 200
From: Bay Area Ca.
I am in Mass and got the recall, my understanding is that Mass adheres to the California rules.
Does anyone know if a car will still pass inspection if this recall is not completed? I wonder if emission related recalls require manufacturers to submit a list of VINs to the state inspection agency, and if they update the list when a car has the recall done.
I have to assume that states who use CARB will fail your inspection for emission recalls that are not completed...unfortunately..
Does anyone know if a car will still pass inspection if this recall is not completed? I wonder if emission related recalls require manufacturers to submit a list of VINs to the state inspection agency, and if they update the list when a car has the recall done.
I have to assume that states who use CARB will fail your inspection for emission recalls that are not completed...unfortunately..
Access to the cars computer is needed for refresh as well as gaining vital information for the certificate of compliance that is needed for renewing registration. Everything nowadays in tracked via computer.
The car may or may not pass your States testing depending on if the sniffer is still used and if the cats are plugged. The cats still might perform well but California does not want to take any chances. We no longer have the tail pipe test on newer models. Just the OBD11 test for system readiness and the visual inspection.
Instructor
Joined: Nov 2007
Posts: 137
Likes: 0
From: Massachusetts
The recall is voluntary but California wants it done prior to registration.
Access to the cars computer is needed for refresh as well as gaining vital information for the certificate of compliance that is needed for renewing registration. Everything nowadays in tracked via computer.
The car may or may not pass your States testing depending on if the sniffer is still used and if the cats are plugged. The cats still might perform well but California does not want to take any chances. We no longer have the tail pipe test on newer models. Just the OBD11 test for system readiness and the visual inspection.
Access to the cars computer is needed for refresh as well as gaining vital information for the certificate of compliance that is needed for renewing registration. Everything nowadays in tracked via computer.
The car may or may not pass your States testing depending on if the sniffer is still used and if the cats are plugged. The cats still might perform well but California does not want to take any chances. We no longer have the tail pipe test on newer models. Just the OBD11 test for system readiness and the visual inspection.
As far as Registration renewal goes...the recall letter mentions CA specifically...
I'll dig a little more, but if I can confirm that the car will pass inspection and renew registration...I'm not going to allow the exhaust system on a low mileage car to be mucked with
