service engine code po430
Thread Starter
On The Tree
Joined: Apr 2004
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service engine code po430 I currently installed ppc lth with high flow lid, high flow cat's and cat back, I also installed granatelli high flow mass air with cold air tunning but I have currently removed it because the car just dosen't run good with it. I place the stock mass air back but I continue to get po430 which is catlalyst system efficiency below threshold bank 2, what can be causing this and how can I correct it.
How many miles on your car? This code is usually caused by a bad cat, or slow functioning rear 02 sensor(usually bad cat) if your car is under 80K the cat is covered under a federal emissions warrenty.
Thread Starter
On The Tree
Joined: Apr 2004
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the car only has 20,000 miles, although I recently had the 8 cylinder misfiring and had to change the plugs which corrected the problem but the car ran about 10 miles with the cylinder misfiring could this have damaged the brand new random technology cats or could it just be the o2 sensor got damaged when I had the long tube headers installed.
On the tree
Joined: May 2004
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My car got the same code, but it was because the dealer replaced one of my cats at 28,000 and not the other one. I had the other one done under the federal warranty. You will not be able to get any help from the dealer due to replacing the cats before the 80000 mile mark. But mine was from the cats showing different effic. rates due to them different miles on them.
TECH Resident
Joined: Jan 2002
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From: USA
The PCM performs the catalyst diagnostic at idle when the conditions for running the diagnostic are met. Refer to Conditions for Running the DTC in DTC P0420 or P0430 in service manual.
During the catalyst diagnostic the PCM captures the current rear (S2) HO2S rich/lean status. The Air Fuel ratio transitions from rich to lean or lean to rich depending on the initial captured rich/lean status.
The Air Fuel ratio transitions a second time opposite the first Air Fuel ratio transition. During this diagnostic the scan tool will display HO2S voltages going from full rich to full lean. This condition is normal during this diagnostic.
The catalyst monitor diagnostic is sensitive to the following conditions:
Exhaust leaks
HO2S Contamination
Alternative fuels (Ethanols and Methanols)
Exhaust system leaks may cause the following:
Prevent a degraded catalyst from failing the diagnostic
Cause a false failure for a normally functioning catalyst
Prevent the diagnostic from running
During the catalyst diagnostic the PCM captures the current rear (S2) HO2S rich/lean status. The Air Fuel ratio transitions from rich to lean or lean to rich depending on the initial captured rich/lean status.
The Air Fuel ratio transitions a second time opposite the first Air Fuel ratio transition. During this diagnostic the scan tool will display HO2S voltages going from full rich to full lean. This condition is normal during this diagnostic.
The catalyst monitor diagnostic is sensitive to the following conditions:
Exhaust leaks
HO2S Contamination
Alternative fuels (Ethanols and Methanols)
Exhaust system leaks may cause the following:
Prevent a degraded catalyst from failing the diagnostic
Cause a false failure for a normally functioning catalyst
Prevent the diagnostic from running
