Happihank

2005 Z51 78000 miles. Engine Light came on several months ago- had it scanned said catalitic converter needed replacing. Light went off- did not replace convertor. Driving to work today light came on again. Called On Star - scanned the car - said engine / ehaust indicator. They said drive at at high speeds for over a period of 7 days, if light doesn't go off go to dealer. Check for loss of power.

Im not making this up! To replace one of the cats is $700 clams parts and labor, so Im hoping light go off. Looking forward to driving at high speeds howverer

tennblkc6

if you are stock one good thing is that the stock cats are a dime a dozen...maybe not in cali tho.

Gearhead Jim

Seven days at high speed? I can't go for more than a couple of hours at high speed before getting low on fuel.

hrt vlv

But officer onstar tech told me to drive at a high speed!!!!!!!!!!!!!!!!

tblu92

Cats typically are good for about 10 years---After that they break down and don't work as well---Only in cailf they are pricey but in other states they are cheap
One more thing-----Your car has 4 02 sensors the front 2 run the AFR for all the P/T fueling
The REAR 02's are there simply to report the "condition of your cats" They don't have anything to do with engine fueling at all--- You may simply have a bad rear 02--- you can change both rears for less than $100 in parts--- Quite often it's the sensors that fail 1st and not the cats---

Happihank

Thanks for the info- and Ill be sure to tell the Officer when I get pulled over for doing 100 - "On Star told me to do it!"

black.z51.c6

If your cats are not clogged and not losing power you can bypass the rear o2sensors by tricking them into thinking that everything is working properly… I did this on my Honda Accord after gutting the catalytic converter and after thousand miles no check engine light basically you get to spark plug non-followers drill half inch hole through one of them and put both on the end of the O2 sensor
http://www.civicforums.com/forums/229-electrical/329421-diy-o2-sensor-bypass-spark-plug-non-fouler-trick-installation-w-pics.html

black.z51.c6

http://www.civicforums.com/forums/229-electrical/329421-diy-o2-sensor-bypass-spark-plug-non-fouler-trick-installation-w-pics.html

black.z51.c6

You will have to cut and paste the link im on my phone

torquetube

When was your car first sold?

Dealers still had some '05s on the lot by mid-December 2006. If yours was one of them, the catalytic converter is still covered under the 8-year/80,000-mile federal emissions warranty (barely).

Happihank

I bought my car in Sept 2004- As far as I know all warenties have expired. Being an early deleivery of a Z51 C6 over the years things like roofs, water pump, fan, fuse box, brakes, etc have been replaced. Some under warrenty some not. Its a M6 so I love it…,what can I say? Im just another dumb vette lover.

torquetube

It was a long shot, but it would be a shame to have _just_ missed out on the warranty period.

Do you know what trouble code is set?

Happihank

Dont remember the code- I should. Light is still on- took it for a high speed ( 1 hour ) run up the 101 this saturday early AM. If the light is still on next week Ill deal with it then. The car is running great….no speed lag, no smell of rotten eggs…who knows? Thanks for your help.

tblu92

They used to make "rear 02' simulators" that would eliminate any rear 02 codes caused by aftermarket exhaust or long tube headers---Just a few years ago they quit selling them and they became illegal----You still may be able to find some and that would correct your problem----if not go to a local tuner--OR get a mail order tune for $150 and tell them what your codes are and why your car won't pass---and they will fix it for you !!

Happihank

Thanks! BTW the light went off..