$800 Chasing Down a P0420 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

'10CamaroDude · 01-27-2020, 04:07 PM

First, it was both sides. Down-pipes were replaced, new cats on those, and
now it's been Bank 1. I am willing to bet they're not OEM down-pipes though.

Both sensors were replaced. The place was not clear on which ones they replaced.
I would think the downstream ones are the critical ones for determining the inefficiency.

I may have to use an O2 spacer on Bank 1, they go on the downstream sensor?

DSX_Camaro · 01-27-2020, 04:27 PM

Yes to downstream. Visual is easy. If you have 4 cats they're OEM.

Downstream sensors are emissions, upstream are air fuel. Could definitely ask which set was done.

'10CamaroDude · 01-27-2020, 04:51 PM

You can buy aftermarket down-pipes with Cats, they're all over eBay. They're $115 a
side on eBay, from Canada, and other places. He should have gotten CARB approved
CATs, even if they were aftermarket, to be safe. I won't know till I get all the paperwork.

MagnaFlow also has a set, but are more than triple the cost per side.

Canada:
https://www.ebay.com/itm/Chevy-CAMAR...0/233354171000

Magnaflow:
https://www.ebay.com/itm/Magnaflow-5...L/143360945327

This just says AP FEDERAL:
https://www.ebay.com/itm/Catalytic-C...E/392556104170
Costs the same as the Magnaflow.

Then there are the Walker brand, for the high $300s.

So, they're gonna try a spacer on Bank1.

'10CamaroDude · 02-01-2020, 11:39 PM

Okay, so here is an update.

The code is P0430, Bank 2, which is the passenger side. Apparently this person
can't remember 20 from 30, or it switched sides with the spacers... If it WAS
20, and now 30, then all I should have to do is remove the spacer on Bank 2,
and all is fine.

Well, three sensors are Bosch, one is AC Delco. I am hoping the AC Delco is on
the driver side. I do not know which one is the AC Delco, but the failure as the
same with all four being Bosch. It has been reduced from both banks, to one.

Also, both downstream sensors have the anti-foulers on them. I doubt the
ends were drilled to 1/2 inch like most videos say. For Euro cars, they can
go in as is, but other cars, they say to drill out the hole to 1/2". Some
are putting steel wool in the spacer when put in out of the package.

The voltages match on both sensors match a lot more on Bank 2.
Fuel trim at idle is negative more on Bank 2. Diagnostic information says
when both sensors read the same, that triggers the CEL for the P0420,
P0430 or both.

I can get the MINI CAT spacers, or try steel wool or stainless mesh in the
passenger side spacer before drilling the end out to 1/2"

So, that is where I am at now, P0430, after new cats, new sensors, and
from both sides having codes, to one side now.

'10CamaroDude · 02-03-2020, 02:50 PM

I contacted the idiot, and he can't remember what he said what code it was. I
know it's P0430, but if it went from P0420 to P0430 after the spacers, then the FIX
is removing Bank 2 spacer... I will try it anyway, just in case.

01-27-2020, 04:07 PM	#1
'10CamaroDude Account Suspended Drives: 2010 Camaro LS Join Date: Nov 2019 Location: Pgh Posts: 739 View My Garage	$800 Chasing Down a P0420 First, it was both sides. Down-pipes were replaced, new cats on those, and now it's been Bank 1. I am willing to bet they're not OEM down-pipes though. Both sensors were replaced. The place was not clear on which ones they replaced. I would think the downstream ones are the critical ones for determining the inefficiency. I may have to use an O2 spacer on Bank 1, they go on the downstream sensor?

01-27-2020, 04:27 PM	#2
DSX_Camaro Drives: 2013 SW 2LT/RS LFX/AY6 Join Date: Feb 2013 Location: Orlando, FL Posts: 1,741	Yes to downstream. Visual is easy. If you have 4 cats they're OEM. Downstream sensors are emissions, upstream are air fuel. Could definitely ask which set was done. __________________ K&N CAI, 1LE Strut Tower Brace, Elite Engineering Catch Can and Clean Side Separator, Apex Scoop w/ Washer Relocation Kit, CTS Front Calipers and Rotors, JacFab Ported Intake Manifold, JacFab Intake Manifold Spacer, 80mm Overkill Throttle Body, SS Brake Lines, Ideal Garage Master Cylinder, Monster Twin Disc Clutch, NPP Retrofit w/ Magnaflow Resonated X, ARH Catless Downpipes, JRE Built 3.45 Diff, 1LE Axles, 1LE Hubs, Overkill Tuned, BMR Anti Wheel-hop Kit Stage I, ACS TL1 Hood Insert, ZL1 Spoiler

02-01-2020, 11:39 PM	#4
'10CamaroDude Account Suspended Drives: 2010 Camaro LS Join Date: Nov 2019 Location: Pgh Posts: 739 View My Garage	Okay, so here is an update. The code is P0430, Bank 2, which is the passenger side. Apparently this person can't remember 20 from 30, or it switched sides with the spacers... If it WAS 20, and now 30, then all I should have to do is remove the spacer on Bank 2, and all is fine. Well, three sensors are Bosch, one is AC Delco. I am hoping the AC Delco is on the driver side. I do not know which one is the AC Delco, but the failure as the same with all four being Bosch. It has been reduced from both banks, to one. Also, both downstream sensors have the anti-foulers on them. I doubt the ends were drilled to 1/2 inch like most videos say. For Euro cars, they can go in as is, but other cars, they say to drill out the hole to 1/2". Some are putting steel wool in the spacer when put in out of the package. The voltages match on both sensors match a lot more on Bank 2. Fuel trim at idle is negative more on Bank 2. Diagnostic information says when both sensors read the same, that triggers the CEL for the P0420, P0430 or both. I can get the MINI CAT spacers, or try steel wool or stainless mesh in the passenger side spacer before drilling the end out to 1/2" So, that is where I am at now, P0430, after new cats, new sensors, and from both sides having codes, to one side now. Last edited by '10CamaroDude; 02-03-2020 at 02:49 PM.

01-27-2020, 04:51 PM	#3
'10CamaroDude Account Suspended Drives: 2010 Camaro LS Join Date: Nov 2019 Location: Pgh Posts: 739 View My Garage	You can buy aftermarket down-pipes with Cats, they're all over eBay. They're $115 a side on eBay, from Canada, and other places. He should have gotten CARB approved CATs, even if they were aftermarket, to be safe. I won't know till I get all the paperwork. MagnaFlow also has a set, but are more than triple the cost per side. Canada: https://www.ebay.com/itm/Chevy-CAMAR...0/233354171000 Magnaflow: https://www.ebay.com/itm/Magnaflow-5...L/143360945327 This just says AP FEDERAL: https://www.ebay.com/itm/Catalytic-C...E/392556104170 Costs the same as the Magnaflow. Then there are the Walker brand, for the high $300s. So, they're gonna try a spacer on Bank1.

02-03-2020, 02:50 PM	#5
'10CamaroDude Account Suspended Drives: 2010 Camaro LS Join Date: Nov 2019 Location: Pgh Posts: 739 View My Garage	I contacted the idiot, and he can't remember what he said what code it was. I know it's P0430, but if it went from P0420 to P0430 after the spacers, then the FIX is removing Bank 2 spacer... I will try it anyway, just in case.