Installed Kooks long tube headers w/ Hi flow cats and X pipe. Check Engine light comes on and readout indicates right and left bank cats inefficient. Not good. Did a road test and the 4 O2 sensors read normal at speed but dropped off to 0 milovolts under decelleration then return to normal under acceleration. Any thoughts on possible problem and resolution.
Reprogramming was attempted but failed on two occasions. Input will be greatly appreciated. I understand O2 simulators are no longer available. Thanx gents. Rad

 

The cats dont warm up enough. Coated headers don't seem to have the problem as often. A tune will turn off the code- permanantly. From what has been poswted on the forum, the kooks are less touchy to the o2 sensors and LG the most without tunes. But that is just what has been posted on this board over the last year or so.

 

Also, make sure you didnt cross the O2 cables. It is very easy, since they come out of the X pipe at an angle where they cross over each other and the natural way they lay, would be crossed (I did this, but remembered to double check and found it before I was done).

 

I have the same problem, I just installed Super Max a week ago, it is the rear O2s and they are reading rich, You will need to have the car tuned in order to change the temp to read higher so the 0420 and 0430 codes do not come up, I cleared the codes but as soon as the cats get hot the codes come back

 

No codes with American Racing Headers!

 

It does not happen with just headers only when you have hight flow cats and the x-pipe the rear O2s go off when reading the fuel mixture

 

I have American Racing headrs with hi flow cats, x pipe, no tune, and best of all no codes. I will be getting the car dyno tuned at A&A next month. You certainly would get codes with headers only (no cats and no O2 sensors) unless you used O2 simulators.

 

How do you clear the codes? I had no codes for several days after insalling Dynatec long tubes with cats. Now check engine lite is on.

 

Gene Gorman; You need a code reader/resetter to erase codes BUT you can temporarily remove them by disconnecting the neg. battery post for a few minutes. If you buy a reader make sure it's CAN enabled for use on C6's. The codes will come back until you get the ECM modified.

achilds; No vendor that I've found has O2 simulators for the C6, they all tell me that the C5 simulators won't work. The only solution is a computer tune.

The above statements are true for only the P0420 & P0430 codes on my car. Other O2 sensor codes may be different.

 

Kooks and hi flow cats with no codes.....until the o2 sensor wire melted???? the dummy that did the headers extended my o2 sensor wire with cheap wire and rubber tape Problem was fixed with the proper o2 extensions.

 

Who makes AMERICAN RACING HEADERS??American racing??LINK PLEASE.
Just when I am starting to contemplate which headers to go with,this stuff comes up again!!

 

Walmart sells a code reader for $70.00 MADE BY "iNNOVA" DONT BUY THE ONE FOR 99.00 IT WONT WORK. STICK WITH THE CHEAPER ONE.....IT WORKS GREAT AND CLEARS ALL CODES.....MAKE SURE YOU GO TO A WALMART WITH AN AUTO CENTER.

 

You can get them from the vette doctors, the website is www.thevettedoctors.com. They are made by American Racing Headers www.americanracingheaders.com. They are very well built product and the install is easy.

 

Thats a fact. No codes for me either. Here`s a link to my write up w/ pics of install.

http://forums.corvetteforum.com/show....php?t=1441406

 

07 A6 with Kooks coated 1-3/4 headers, with 3inch hi flow cats and x-pipe. I have the 0430, and 0420 codes as well. Happen about every 50-75 miles. Guess I need a tune!

 

American Racing 1-7/8" Headers w/x-pipe & hi-flow cats. No error codes.

 

So how does a tune get rid of the CEL? Do they just delete the rear O2 senser banks in the ECM?

 

I went by the Super Walmart for that specific reader and they didnt have them, I didn't want to go through the process of looking through other places that might have them or not, just went by amazon and searched for them...and "poof" and got them in the mail a few days later

 

300+ miles and 20 days since install. No Cel, No Tune.

Kooks 1 3/4 (jethotted coated) headers.
Kooks Hi-Flow Cats.

i agree, at least from what i've read here, it appears that coated headers don't throw as many cels as uncoated.

i'm not sure i understand what was meany by 'crossing the extensions.'

my rear o2 sensors basically form an x, due to the way they come out of the cats, they are both pointing up and with an angle toward each other. the extension wires are tucked-up and wire tied to the tunnel plate (yep, drilled two holes in it) and routed forward. they run next too and on top of each other for a bit.

other possible causes of header install related cels can be:

contaiminated sensors (i simply reinstall them dry, no need for no goop).
burnt extension wires.

too much heat being passed to the rear sensor. i'll explain that one.
if the variance between the two sensors (front to rear) is not great enough (front needs to be hotter) the system will understand this to mean the cat has failed or is not working properly.

it may be possible that some uncoated headers are not retaining enough heat in the collector (where the front o2 sensor is located), which causes the front sensor to read one temp, but when the cats. heat up, the rear sensor is getting hotter than the front sensor and causing a 'cat' related code.

 

To clear the codes, you do not need to disconnect the battery, which will reset your clock, possibly disable the window indexing, etc. WIth the engine off, just open the fuse box and pull out the ECM fuse, then replace it. The fuse box even has a little fuse puller for your convenience.