What causes P0430 Catalyst System Efficiency Below Threshold (Bank 2)
Thread Starter
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
What causes P0430 Catalyst System Efficiency Below Threshold (Bank 2)
Came on tonight..... I cleared it and it hasn't come back... I have Kooks LT headers w/ hi-flo cats an no tuning... last time I dyno'd it it was 11.5:1 up top but nothing bad. I've had them for almost a year now w/o any codes.
Any ideas?
Any ideas?
Last edited by Cobra4B; Dec 23, 2004 at 01:14 AM.
Burning Brakes
Joined: Feb 2003
Posts: 1,143
Likes: 111
From: Windsor ON
I have codes 420 & 430 which means that both my cats are operating at low efficiency. I also have the 1 3/4" Kooks w/ cats and no tuning. From what I've read some cars throw these codes with exhaust mods, some don't. They came up after about 50mi. of driving and reappear even after I erase them after some driving time. It's wierd your just getting a code now, but I wouldn't worry too much about it. 
Last edited by 97 SC Cobra; Dec 23, 2004 at 02:04 AM.
Melting Slicks
Joined: Jan 2001
Posts: 2,635
Likes: 2
From: Aloha, Oregon
For either code 420 or 430: The PCM measures the time it takes the rear HO2S voltage to cross a reference rich-to-lean threshold, minus the time it takes the front HO2S voltage to cross the same rich-to-lean threshold. The difference between the front O2 sensor time and the rear O2 sensor time is the oxygen storage capacity of the catalyst. This DTC sets if the time exceeds a predetermined threshold.
These thresholds can be adjusted using Edit V1.5.
Robert
These thresholds can be adjusted using Edit V1.5.
Robert
Team Owner
Joined: Mar 2002
Posts: 47,647
Likes: 1
From: Queens, New York Life begins at 183 mph....
St. Jude Donor '08-'09
I've got the same problem. It pops up every 100 miles or so ever since I got my kooks LT headers and hi flow cats. I just haven't had time to go there to have it edited out using LS1-edit. Other threads have mentioned that the edit will get rid of the problem. I'll probably wait till the weather gets better and do my T-stat at the same time.
