yep, i have the magnafolw cat too. and my maf sensor is brand new yet it still throws the code. i dont know how im going to get the code removed from the pcm though. i need the car its my daily driver.

 

You can contact Jason, themaniac, and talk to him about buying a used pcm and shipping it to him. He then can program the PCM to tune out all the codes caused by the aftermarket cat and add any of his other services if you want and ship it back.

 

Thanks! I sent him a PM and will give it a shot. now all i need to do is find a way to turn off these daytime running lights.

 

x2, nothing has been wrong with your catalytic converters. Unfortunately you wasted a lot of money each year

The stock parameters are so tough to get out of the aftermarket, that the PCM just assumes something is wrong.

Simply using a sparkplug defouler trick, or getting the code deleted from your PCM is the easiest way to pass inspection.

 

P0141 should not be a problem with the cat. It's a problem with the downstream O2. Per the GM Shop Book:
Now, the P0420, here's a blurb from the shop book about that:
HO2S 1 - Upstream (pre cat)
HO2S 2 - Downstream (post cat)

 

So am I understanding right, that the best way to stop theses codes after installing an aftermarket catis to have them removed from the PCM?

 

Yes and no. First, depends what codes you are talking about.
The issue is that the PCM is tuned in such a way to be tight to the factory cat specs. So you can install an aftermarket one (does not even have to be a high flow) and even if it's perfectly fine, it may not meet the strict specs of an OEM cat. The ONLY code I am aware of for that situation is a P0420 code (all the other codes are unrelated and indicate a malfunction).

The P0420 code has plagued people not even trying to mod a car. This code was to measure the "health" of your cat and alter you to a failing cat. The spark plug defouler works by pulling the O2 sensor probe out of the main exhaust stream and therefore is not reading the stream near as accurate as it otherwise would, thus preventing the P0420 code.

The cleanest way to rid a P0420 code is having it deleted from the PCM (another words, the PCM is not testing/checking/recording anything for the P0420 code).

 

ok, no way i am burning out o2 sensors that fast without something else of major issue on my motor. Like i said, i change BOTH and it holds long enough to get me through inspection. A few days at best. this is something i have done for the past few years now.

So my question is, if I am really burning through TWO brand new o2 sensors in 2 to 3 days not matter how often or what brands, them wheres my issue? And shouldnt there be some sort of problem causing them to go bad so often? And a code to indicate such?

 

For the P0420 code, yes just deleting it or using the spark plug defouler is the best method.

For the codes referring to the pre-cat o2 sensor, I would think something has to be wrong with the wiring.