I have a C6, Z51 6-speed with long-tube headers (Dynatech) with high-flow cats. I have had them for about 6,000 miles with no codes (after the first week). The car runs perfectly. I have a code "P0430 Catalytic system efficiency below threshold (Bank 2)." This was not one of my first week codes. The Chevy dealer said that it is probably a bad O2 sensor on the driver's side behind the cat. He said that it may also be the wire. Have any of you had this? What did you do? Thanks for the help.

 

IF YOU HAD IT TUNED ITS A GLITCH IN THE PROGRAM IF NOT GO GET IT TURNED OFF the code is a low flowing cat right bank so you no its not have it programed off

 

I was wondering the same thing that dennis50nj mentioned - do you have a tune? I think most tunes for long-tube headers will disable the rear O2 sensors.

Did you do anything to your tune recently?

If you have a Predator and put in the factory tune prior to a visit to the dealer, just put your custom tune back in and you'll be fine. We had another forum member that had this same code recently and that was his problem.

If you don't have a tune, you might consider getting one. It will take care of this problem and really wake up the car and take advantage of your mods. At least on my car with Kooks and high-flow cats, even my Predator "custom" tune (which is nothing like a full-blown custom dyno tune) really perked my car up. A tune is a good thing.

Bob

 

I did have a tune the weekend before last on Saturday. I also had a Honker and a FAST intake manifold installed on Thursday and Friday, respectively, but this problem showed up 8 days and over 150 miles later. As I said the car runs great. It has a lot more power, sounds better and gets better gas mileage. Unfortunately, my Bank 2 catalytic system is acting up. Thanks for your comments.

 

P0430 Catalyst System Low Efficiency Bank 2 ECM. It is nothing just reset it. Here is the list of codes for future reference.

http://www.corvetteactioncenter.com/....php?qstId=566

 

Disconnect the battery for 30 seconds and power back up to erase the code and see if it comes back.

To the response on turning off a code....bad idea. The tuning of headers should never require the deleteing of a code. In this case the Cats didnt heat up fast enough and tripped the code.

 

I had this code for a while. we sorted this out and tracked it down to a damaged O2 sensor wire (common in header installations with a tunnel plate). Once the O2 sensor was replaced the code never came back (7k+ miles). Others have eliminated this code with tuning. I do not receommend turning the sensor off.

 

Thanks, Gents. I'll follow up on your recommendations and let you know what happened.

 

I have the same problem. Ordered O2 simulators, hope this will take care of the problem.

 

I disconnected the battery for the recommended 30 seconds. There was no code when I fired 'er up. Thanks SpinMonster! Thanks also to others who offered advice and observations, similar and otherwise.

I discussed this today with another wise man at Dynatech. He explained that the subject cat/sensor combo might have been overwhelmed by the recent changes (tune/Honker/FAST) as they interacted with the car's computer to deal with the new air/fuel/spark situation. He also recommeded the reset strategy.

He also explained that we may have to do the reset more than once and that there is a back up strategy, too. If the reset doesn't work after repeated attempts, we can try anti-fouling washers (Chevy small-block spark plug voodoo available at Pep Boys/Auto Zone.) applied at the rear O2 sensor/bung junction. Apparently, two are required per side. The first has to be drilled to fit the sensor and the other just fits after that. When reassembled, the sensor is just far enough in the stream to do it's job but not so far in to be too sensitive to do it's job. I won't profess to understand this well enough to present the lecture at the engineering school tomorrow but it sounds "reasonable."

Thanks again to all. Hopefully this is it.