Need help with emissions report codes

mr360 · 10-07-2008, 10:12 AM

Failed emissions, does anyone know what the following codes means and what I can do to get it to pass:

"PO420 Catalyst System Efficiency Below Threshold (Bank 1)"

muffinman · 10-07-2008, 10:35 AM

This is what i found but you've probably already read this:

Code P0420 is a code for Catalyst efficiency. The computer is seeing the post Catalytic converter o2 sensor having too much activity. The Cat. should be cleaning the exaust of Hc, co, and Nox. The post cat o2 will read the o2 content in the exhaust and if it moves up and down too much or to high and low, the computer interperates that as the cat not ridding the exhaust of it's pollutants. The problem could be a bad cat, o2 sensor (Pre- and/or post cat)or o2 sensor wires, or an air fuel mixture problem that has caused the cat to fail.

supunna_picta · 10-07-2008, 10:54 AM

Quote:

Originally Posted by mr360

Failed emissions, does anyone know what the following codes means and what I can do to get it to pass:

"PO420 Catalyst System Efficiency Below Threshold (Bank 1)"

muffinman gave you the right code definition.

Are you running a stock exhaust system or modified? If stock, most likely just a bad 02 sensor - bank 1 being pre-cats IIRC (there are three 02 sensors in the spyder).

If you are running an aftermarket header with a 2 sensor set up it could be wiring related.

lbridges · 10-07-2008, 06:22 PM

The BGB says, "After engine and catalyst are warmed up, and while vehicle is driven within set vehicle and engine speed range, waveforms of oxygen sensors (bank 1 sensor 1 and bank 1 sensor 2) have same amplitude (2 trip detection logic)." So it is comparing the sensor inthe pre-cat area with the sensor at the main cat.

Which leads one to suspect one of three things:
Gas leakage on exhaust system (probably failing at header to down pipe joint)
Bank 2 oxygen sensor (if the heater part failed - typical - you "should" also get 0136, but...)
Three-way catalytic converter failure

Ben · 10-08-2008, 01:06 AM

Toyota's emissions warranty is 8 years, 80,000 miles. If you are in the range, the dealer might warranty the failed part. But check with them first

mr360 · 10-09-2008, 08:55 AM

Thanks for all the help. Ben, I am not the original owner so I will probably will not be able to get it covered under the warranty.

Ben · 10-10-2008, 01:00 AM

If it is under factory warranty, it doesn't matter if you are the original owner or not.

10-07-2008, 10:12 AM	#1 (permalink)
mr360 No Skills Join Date: Aug 2008 Posts: 10 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Need help with emissions report codes Failed emissions, does anyone know what the following codes means and what I can do to get it to pass: "PO420 Catalyst System Efficiency Below Threshold (Bank 1)"

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10-07-2008, 10:35 AM	#2 (permalink)
muffinman Cage Fighter Join Date: Jan 2008 Posts: 586 Thanks: 13 Thanked 36 Times in 36 Posts iTrader Rating: (0/0% )	This is what i found but you've probably already read this: Code P0420 is a code for Catalyst efficiency. The computer is seeing the post Catalytic converter o2 sensor having too much activity. The Cat. should be cleaning the exaust of Hc, co, and Nox. The post cat o2 will read the o2 content in the exhaust and if it moves up and down too much or to high and low, the computer interperates that as the cat not ridding the exhaust of it's pollutants. The problem could be a bad cat, o2 sensor (Pre- and/or post cat)or o2 sensor wires, or an air fuel mixture problem that has caused the cat to fail.

10-07-2008, 06:22 PM	#4 (permalink)
lbridges No Skills Join Date: Jul 2006 Location: East Central FLA Posts: 123 Thanks: 1 Thanked 10 Times in 10 Posts iTrader Rating: (0/0% )	The BGB says, "After engine and catalyst are warmed up, and while vehicle is driven within set vehicle and engine speed range, waveforms of oxygen sensors (bank 1 sensor 1 and bank 1 sensor 2) have same amplitude (2 trip detection logic)." So it is comparing the sensor inthe pre-cat area with the sensor at the main cat. Which leads one to suspect one of three things: Gas leakage on exhaust system (probably failing at header to down pipe joint) Bank 2 oxygen sensor (if the heater part failed - typical - you "should" also get 0136, but...) Three-way catalytic converter failure

10-08-2008, 01:06 AM	#5 (permalink)
Ben Propulsion Restored Join Date: Aug 2006 Location: Oceanside, CA / Reno, NV Posts: 3,280 Thanks: 18 Thanked 235 Times in 222 Posts My Google Map iTrader Rating: (10/100% )	Toyota's emissions warranty is 8 years, 80,000 miles. If you are in the range, the dealer might warranty the failed part. But check with them first

10-09-2008, 08:55 AM	#6 (permalink)
mr360 No Skills Join Date: Aug 2008 Posts: 10 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Thanks for all the help. Ben, I am not the original owner so I will probably will not be able to get it covered under the warranty.

10-10-2008, 01:00 AM	#7 (permalink)
Ben Propulsion Restored Join Date: Aug 2006 Location: Oceanside, CA / Reno, NV Posts: 3,280 Thanks: 18 Thanked 235 Times in 222 Posts My Google Map iTrader Rating: (10/100% )	If it is under factory warranty, it doesn't matter if you are the original owner or not.