What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[George B]

can't get this p0420 code to go away so ordered 4 new 02 sensors as a gamble just to see $177.00
if that doesn't fix it I will try and get the cat warranted but doubtfull, stupid thing is only 6 months old, the 02 sensors are about 5 years old with 75k on them.
something seems to be borderline the code will come up after 3-4 days right before it should be ready

When I had a bad cat I had the same symptoms. It took a while to run the monitor test, it would fail, and flag a code. That was on my NBS tho

 

[Doubeleive]

When I had a bad cat I had the same symptoms. It took a while to run the monitor test, it would fail, and flag a code. That was on my NBS tho

I have had cat's go bad before but not in 6 months that's just crazy, getting close to time to do the 02's anyway so figured it might be worth a gamble
at least I can tell the shop that installed it that I tried everything.

 

[RooTBeeRthe1st]

can't get this p0420 code to go away so ordered 4 new 02 sensors as a gamble just to see $177.00
if that doesn't fix it I will try and get the cat warranted but doubtfull, stupid thing is only 6 months old, the 02 sensors are about 5 years old with 75k on them.
something seems to be borderline the code will come up after 3-4 days right before it should be ready

That's a fun one to chase down

 

[alpha_omega]

That's a fun one to chase down

I was just thinking the same thing. Nothing like replacing all four and the cat…only for the code to pop back up. Mother*^•k€r$!

 

[iamdub]

Loaded it up with tools and a 6' ladder to bring to my brother's house to replace the springs on his garage door.

 

[RooTBeeRthe1st]

Loaded it up with tools and a 6' ladder to bring to my brother's house to replace the springs on his garage door.

Doing work!

 

[Doubeleive]

That's a fun one to chase down

well it should simply be a bad cat, but if a 02 sensor is giving slightly incorrect information it could be a problem if anything it would likely be the downstream but I am not going to screw around and just try 1. If that doesn't work then at least I will not have to worry about the sensors for a good while again.
sensors should probably be here Monday I will put them in and reset the fuel trims and cross my finngers.
truck runs fine, I might even just have the code turned off and say screw it until it's time to have it smogged again, c.a.r.b cat's are not cheap right now

 

[RooTBeeRthe1st]

well it should simply be a bad cat, but if a 02 sensor is giving slightly incorrect information it could be a problem if anything it would likely be the downstream but I am not going to screw around and just try 1. If that doesn't work then at least I will not have to worry about the sensors for a good while again.
sensors should probably be here Monday I will put them in and reset the fuel trims and cross my finngers.
truck runs fine, I might even just have the code turned off and say screw it until it's time to have it smogged again, c.a.r.b cat's are not cheap right now

Even though I already have the actual physical flex fuel sensor, once I found out that it was likely my oxygen sensors causing the calculations for the ethanol content to be off prior to installing the sensor, I bought new sensors. And have had them for a long time and have not installed them yet.
So I'm wondering if even though the sensors I have in it now are relatively new. Only a few years, they were not OEM spec necessarily, so maybe these new sensors will fix that.

 

[Doubeleive]

Even though I already have the actual physical flex fuel sensor, once I found out that it was likely my oxygen sensors causing the calculations for the ethanol content to be off prior to installing the sensor, I bought new sensors. And have had them for a long time and have not installed them yet.
So I'm wondering if even though the sensors I have in it now are relatively new. Only a few years, they were not OEM spec necessarily, so maybe these new sensors will fix that.

no idea, I know the ones in my 6.2 are heated and have had a rough 75k life, I have had luck before in the past just changing a 02 sensor for a cat code and it worked

 

[Mickey_7106]

Changed the oil yesterday. Ordered some more KnN filters thinking i was out. Anyone else noticed the change in design? The new filter is a bit shorter and it has more holes near the gasket. New and old filter were bought on amazon