Does this mean you will now suffer the same hot right leg as I do in my 4 cat 2012?

 

The recall is voluntary but California wants it done prior to registration.


This is a misunderstanding of the recall letter. GM is "voluntarily" conducting the recall and is not being made to do it by an order from the EPA.

For the individual owner, all recalls are voluntary.

 

Yes alright but the catch is that in California one will not be able to register the car without having the recall performed. Irrespective of the existing cats working or not.

 

They won't put you in jail for not getting a recall. It's voluntary. Now if you want to register your car, that's another matter. We should all be for cleaner air. My opinion.

 

No, they won't put you in jail for not complying with the recall. However, in CA if we don't comply, getting pulled over for expired registration will be a bit of a pain in the azz. So much for a voluntary recall.

 

Didn't want to start a new thread on same topic but I am curious what do the performance shops / vendors think of the recall? Is it truly an upgrade or downgrade for those with stock exhaust and cats.


I have read most of this thread and the "butt dyno" says its faster after the recall.

How about some numbers? Any shops that would run a before and after dyno?

 

Adding two additional catalytic converters (4 total) will add more back pressure which might feel like the car has a little more bottom end. This added back pressure loses a few HP in the midrange and top end. Most likely, not to be felt.

However, we do not know "If" or "Any" improved performance is due to partially clogged catalytic converters or a the reprogramed ECM. Without comparing the original to the new ECM files, one can only guess that GM leaned out A/F ratio a bit at WOT.


I would prefer GM just replace the original converters and not add two more smaller cats downstream.

To answer your question, it's only an upgrade if your catalytic converters are clogged.

 

it's only an upgrade if your catalytic converters are clogged.

Or if you are trying or intend to sell your car in the future. New cats over 7 to 9 year old cats would make your car more desirable.

 

I received the recall letter on Wednesday, 9-16-2015 on my 2008. Today (Friday) I called GM & went to local Chevy dealer where I've had service performed on my 2008 Vette, including changing leaking oil pan gasket while under warrenty. They do excellent work. GM rep that answered the phone could hardly speak or understand English. I was not happy. Went to local dealer. Left very happy and satisfied after speaking with service manager. I was told in short, after lengthy discussion with the service manager drive it and enjoy it. When and if it ever fails emissions because of the cat's, then have them replaced. A recall notice does not expire. I live in CT, where these emission standards apply, which I still do not understand, along with most of the East coast

 

I also asked about the cat's getting clogged. They are not like the old ones with the beads in them, they have a honeycomb web in them that do not clog or collapse. When they fail, they don't burn the gases going through and register a check engine light. I also asked about registration. I was told that your registration cannot be denied because of a recall. If the dealer was selling a car with a recall and they knew it then yes the registration could be denied but not with the current owner. You can still register your vehicle

 

FYI, honey comb style cats have been in use for a while and can burn up, which includes melting, breaking apart and pieces turning sideways. Then breaking off and working their way into your muffler.

DJ

 

Important message for California residents:

The California Air Resources Board (CARB) requires vehicle emission recalls be completed prior to Valifornia registration renewal. U corrected emission recalls will result in the inability to renew your California vehicle registration.

This is word for word from the letter I recieved from GM concerning the recall.

We out in in the Golden State have no choice.

Regarding clogged I admit my knowledge is outdated, as is a lot of other things.

 

... and if small enough through the muffler. That's one of the reasons when dyno tuning your car, "Never stand in front of the exhaust pipe!"

 

Lots more info from others like myself that had it done.
Long story short, I'm glad I had it done.
Mine runs Noticeably better.

https://www.corvetteforum.com/forums...rs-h-pipe.html

Note: the "Voluntary" part is by GM.
Doubt anyone will come and track people down for not doing it.
But, GM is Voluntarily offering this Recall on their own preemptively, it's not voluntary for the consumer.
Just sayin"

 

Not voluntary in California as already mentioned.

DJ

 

Just got my recall. Curious about before and after dynos.

 

In California, it's a catch 22.
GM, is "voluntarily" offering this recall for free.
But it is not mandatory for GM to do this.
Yes in a sense it's not voluntary for someone in California because if they refuse to do it, they will have to "Pay" for the recall work out of pocket to get their vehicle to pass inspection when the time comes to get it inspected.
If you don't live in California then it's also voluntary for the consumer.

I'm in Mass and my 09 falls under the Cali emissions but, I passed Inspection when I went for a sticker.
That's when they told me about the emissions recall and I had it done a few weeks later
Now whether or not Mass or any other state with Cali standards is going to change how they do sticker/emissions in the future is anyone's guess

 

don't do this if you like the rumble of your dual mode exhaust

2009 z51 7,500mile with dual mode exhaust.

I had this done 2 months ago and the dealer has been trying to get me a solution ever since. Just came from there, they thought they may have found a solution but still no. My issue, the nice rumble at start up basically gone, the instantaneous nice rumble at the push of the throttle gone. You still get some rumble, but not nearly as quick or as nice as it was - I would not recommend this recall for anyone who loves the nice dual rumble of the exhaust option dual mode (also known as Option NPP or dual note or etc).

From what I see some people are happy with this, i.e they have a lot of miles and they got a new cat system for free, they don't mind the lost of the sweat rumble, the performance improved because of bad cats, etc, but if you love the dual mode sound you will probably be disappointed like me.

Some people claim more power some claim less. Without a dyno test before and after I don't know what you can really say. the black marks on the pavement look the same to me before and after. what is lost is that sweet sound!

 

IMO, long story short, you just need different louder Mufflers and you'll be good to go.
And you'll still be able to use NPP with the right setup.
Good Luck

 

I just have the Corsa Sports and I am sure they will be quieter losing the 3in pipe back to 2 1/2in.

One person who will be happy is the wife!

I am resigned now with California be so strict. Which is ok after 7 years I am not driving the car as much.

Sounds like sour grapes maybe but what one going to do? Just tired of fighting the emissions. It is just to costly changing all the time.