2007 5.3 “catalyst efficiency below threshold” bank 1 and 2??!!

[Nate6.0]

5 hours ago, swathdiver said:

 

When ordering my cats, I completely forgot that my truck has California emissions.  So it has Magnaflow federal cats and y-pipe.  I emailed Walker and Magnaflow and others back then and received no response as to what the differences might be between CARB and Federal cats.  No lights after four years and 50K miles.

Funny you are posting this, and it’s leading me to think my federal emissions cats are not the issue. To your question above, from my research the CARB cats may not be any different at all, but require the mfg to warranty them to 8 years / 80k miles so probably many mfg don’t seek the CARB certifications. This would also be supported by your experience with federal magnaflow cats working fine.

[Nate6.0]

Ok took these today…this is after 20

min drive so everything is up to temp.

 

 

Edited November 22, 2021 by Nate6.0

[Nate6.0]

And here is bank 1 sensor 2 

[Nate6.0]

Any Thoughts/feedback on O2 readings? I can get more data if that would help 

[swathdiver]

13 hours ago, Nate6.0 said:

Any Thoughts/feedback on O2 readings? I can get more data if that would help 

 

From what I can tell, it looks normal.  Can you take a video of each and post them to youtube?

 

If the upstream sensors are cycling in more or less unison near the full range then they are good.  If the downstream sensors stay at a steady state more or less, they too are good.

 

One thing I did not say, new cats often throw a code or two within the first 50-100 miles as they are broke in.  You can heat them up by driving around in 2nd gear and getting the RPMs up.  If they keep setting a code though, the computer don't want them around anymore.

[Nate6.0]

19 hours ago, swathdiver said:

 

From what I can tell, it looks normal.  Can you take a video of each and post them to youtube?

 

 

Here is video starts at idle then about half way I rev to 2k and hold at 2k

and here is only idling 

 

both are after a drive so everything is up to temp 

Edited November 25, 2021 by Nate6.0

[Nate6.0]

Bump

 

[swathdiver]

On 11/30/2021 at 2:16 PM, Nate6.0 said:

Bump

 

They look a normal to me, maybe a little slow and not going the full range, watched them a couple of times.  I'm going to ask some other fellas to stop by and read the thread and watch these videos.

 

Hey Fellas, Can you check this thread out and render an opinion please?

 

@doubeleive @Grumpy Bear @shakenfake@diyer2@GrumpyGhost@Black02Silverado

[Grumpy Bear]

On 11/20/2021 at 11:02 PM, newdude said:

 

 

 

Cool.  Looks like I see "NE1" for the emissions RPO option. 

 

NE1 is "Connecticut, Delaware, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Vermont and Washington state requirements" so in short, its spec'd for one of those 13 states that follow CARB vehicle emissions equipment.

 

TLDR, your aftermarket Davico cats that you posted the picture of are Federal Emissions spec cats.  At least with a GM vehicle, if it was built with California Emissions, either as a CA truck or an NE1 truck, they use CARB spec converters.  Federal cats will set P0420/P0430 codes upon installation on a CARB spec'd truck.  The cats aren't as "clean" if you will, and the ECM knows it via whatever data its monitoring for catalyst efficiency and sets the codes.  

 

You need to get a hold of either the OEM y-pipe cat assembly, or find some sort of aftermarket CARB cats for the Davico Y pipe.  It is entirely possible that the y-pipe you had on before did truly fail, or if even it was aftermarket, was causing the same issue.   

 

What's the Difference Between CARB and EPA Catalytic Converters? | Walker Exhaust Systems

 

 

This. There is what we would like to be true then there is what is true. Not always fun. Sorry. 

[doubeleive]

I didn't really gather much from the 02 sensor video but I have seen a bad maf cause all kinds of codes including 02 and cat codes, lean codes, funky transmission shifting, misfire codes, you name it, maybe try monitoring the maf and see what values it is showing

other than that i would monitor 02 bank1 sensor1 and bank2 sensor1 they should be reading approx the same

same for bank1 sensor2 and bank2 sensor2, if one is suspect swap them left & right and see if the pattern follows

[Black02Silverado]

Just curious but what fuel are you running?  If E85 and not an FF vehicle can cause this.  It did on my 2002 Silverado if I ran more than a 50/50 mix of premium and E85.

[shakenfake]

Is your truck stuck in open loop? 

 

You did say you fixed your exhaust leaks correct? I would smoke test the exhaust and then do the intake.

[Nate6.0]

On 12/2/2021 at 9:12 AM, shakenfake said:

Is your truck stuck in open loop? 

 

You did say you fixed your exhaust leaks correct? I would smoke test the exhaust and then do the intake.

How would I determine this if in open loop?

 

Regarding exhaust, yes it’s brand new manifolds, gaskets and cats/ y pipe…I replaced them all thinking my cat efficiency code was due to exhaust leak.  

[Nate6.0]

On 12/2/2021 at 6:12 AM, Black02Silverado said:

Just curious but what fuel are you running?  If E85 and not an FF vehicle can cause this.  It did on my 2002 Silverado if I ran more than a 50/50 mix of premium and E85.

E87 for the 3 months I’ve owned it 

[Nate6.0]

On 12/1/2021 at 11:36 PM, Grumpy Bear said:

This. There is what we would like to be true then there is what is true. Not always fun. Sorry. 

so I can expect an efficiency code until procuring and Installing a CARB cat?