Really need C5 help !!
Thread Starter
Burning Brakes
Joined: Dec 2011
Posts: 858
Likes: 75
From: Medford, Oregon
Really need C5 help !!
It's that dreaded time of the year for me to get the Vette smogged. I lost a 'Good' friend that made this not a major concern but that has gone away. I was hoping that someone local might have their old 'H' pipe with good cats laying around to either buy or 'rent'. I wish I knew the magic way to fool the computer of the P0420-0430 code. I have a 99' that runs really clean on emissions levels that are well with in Ca. guidelines, but I have the 'check engine' light on (naturally) so it automatically fails. Any help from the forum would be greatly appreciated !! 
Le Mans Master
Joined: Jan 2004
Posts: 9,488
Likes: 1,743
From: Knoxville Tn
Surely someone in your area has dismantled a wrecked C-5 and has what you need. If I were you, I'd buy a set and keep them there for those 'trying times'. Check Craig's list and E-bay, you might be surprised what is available.
We have two leaning against the wall here in Knoxville as I type.
We have two leaning against the wall here in Knoxville as I type.
Racer
Joined: Nov 2014
Posts: 286
Likes: 12
From: Cypress TX
A "buddy" of mine has the heated cats I believe turned off with HP Tuners. I, I mean "he", has long tubes with off road xpipe and no check engine light on. Texas allows up to 2 "not ready's" during inspection, not sure what your state requires. Now if you have to have the sniffer hooked up, then some spare cats would be needed.
Pro
Joined: Feb 2014
Posts: 536
Likes: 2
From: Brisbane Queensland
I have absolutely no idea what a California smog inspection entails, so what worked for me may not suit you.
After installing headers, X-pipe, hi-flow cats and Borla exhaust I had the P0420-0430 codes and the CEL. My tuner deleted the O2 sensors from the program and that solved the problem. No codes, no CEL. Don't know if this is legal in California. Probably not!
Having to re-install the stock exhaust just to pass the smog test is a real PIA!
After installing headers, X-pipe, hi-flow cats and Borla exhaust I had the P0420-0430 codes and the CEL. My tuner deleted the O2 sensors from the program and that solved the problem. No codes, no CEL. Don't know if this is legal in California. Probably not!
Having to re-install the stock exhaust just to pass the smog test is a real PIA!
Thread Starter
Burning Brakes
Joined: Dec 2011
Posts: 858
Likes: 75
From: Medford, Oregon
A "buddy" of mine has the heated cats I believe turned off with HP Tuners. I, I mean "he", has long tubes with off road xpipe and no check engine light on. Texas allows up to 2 "not ready's" during inspection, not sure what your state requires. Now if you have to have the sniffer hooked up, then some spare cats would be needed.
Thanks for the response, Ca. has the same allowance of two codes as well for 00'-97', but it's the check engine light being on that screws up the whole process. The thing that irks me me about Ca. is my car runs 'Really' clean and exceeds all levels of emissions required to pass, but because the computer says the cats are below efficient levels a stupid light that's on fails it. I guess with new cats my car should show 'No' levels of emissions, I don't know, I'm just P_ _ _ _d about the regulations in Cal.
Thread Starter
Burning Brakes
Joined: Dec 2011
Posts: 858
Likes: 75
From: Medford, Oregon
I have absolutely no idea what a California smog inspection entails, so what worked for me may not suit you.
After installing headers, X-pipe, hi-flow cats and Borla exhaust I had the P0420-0430 codes and the CEL. My tuner deleted the O2 sensors from the program and that solved the problem. No codes, no CEL. Don't know if this is legal in California. Probably not!
Having to re-install the stock exhaust just to pass the smog test is a real PIA!
After installing headers, X-pipe, hi-flow cats and Borla exhaust I had the P0420-0430 codes and the CEL. My tuner deleted the O2 sensors from the program and that solved the problem. No codes, no CEL. Don't know if this is legal in California. Probably not!
Having to re-install the stock exhaust just to pass the smog test is a real PIA!
I feel that I will be looking into that as soon I can locate a tuner in my area. Thanks brother !!
Team Owner
Joined: Sep 2001
Posts: 23,283
Likes: 906
From: Lake Elsinore, CA
I have a full set of exhaust manifolds, cats and H-pipe that would work for you that i'm not using and have no plans to use. I work in Irvine - you could come pick them up if I bring them to work. Let me know.
Racer
Joined: Feb 2014
Posts: 251
Likes: 60
From: Peru Indiana
It's that dreaded time of the year for me to get the Vette smogged. I lost a 'Good' friend that made this not a major concern but that has gone away. I was hoping that someone local might have their old 'H' pipe with good cats laying around to either buy or 'rent'. I wish I knew the magic way to fool the computer of the P0420-0430 code. I have a 99' that runs really clean on emissions levels that are well with in Ca. guidelines, but I have the 'check engine' light on (naturally) so it automatically fails. Any help from the forum would be greatly appreciated !! Corvette Stories
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Burning Brakes
Joined: Jun 2012
Posts: 803
Likes: 42
From: Destin Florida
Also OP I don't know if they still sell them because every one that does mods now has a tuner cut off certain things BUT you can see of you can find some O2 simulators. Plug these into the rear O2's connectors and you could have no cats and the light will stay off. About 60 bucks for a pair last time I saw them years ago.
Thread Starter
Burning Brakes
Joined: Dec 2011
Posts: 858
Likes: 75
From: Medford, Oregon
Also OP I don't know if they still sell them because every one that does mods now has a tuner cut off certain things BUT you can see of you can find some O2 simulators. Plug these into the rear O2's connectors and you could have no cats and the light will stay off. About 60 bucks for a pair last time I saw them years ago.
Wow, completely forgot about that possibility. Thanks for the heads up, I will try to see if they are still available. Thank you brother for the suggestion !!
Thread Starter
Burning Brakes
Joined: Dec 2011
Posts: 858
Likes: 75
From: Medford, Oregon
Pro
Joined: Nov 2006
Posts: 511
Likes: 64
From: Vancouver BC
This works great. It generates a .5V signal and holds for a bit, then drops to 0V. And repeats. An astable multivibrator. $20 in parts.... https://www.google.com/search?q=o2+simulator+555+circuit&client =ms-android-motorola&source=lnms&tbm=isch&sa=X&ei=pt W5VLD9Mc61ogTb4oHoAw&ved=0CAYQ_AUoAQ&biw =360&bih=511#imgrc=HHGRbxmQ5EVxyM%253A%3 B_eMTLCJCSTGEvM%3Bhttp%253A%252F%252Fi.y timg.com%252Fvi%252Fa1uIQkdU7QY%252Fmaxr esdefault.jpg%3Bhttp%253A%252F%252Fwww.y outube.com%252Fwatch%253Fv%253Da1uIQkdU7 QY%3B1280%3B720