Oxygen sensor's kaput
11-10-2002, 12:46 PM
#1
Senior Member
Thread Starter
Join Date: Oct 2001
Posts: 108
Oxygen sensor's kaput
my service engine light came on and i checked it out. turns out it's a PO 420 (Efficiency below threshold). i'm guessing it's for the oxygen sensor. is that right? also, what's the purpose of it besides sensing oxygen?
11-10-2002, 07:24 PM
#2
Senior Member
Join Date: Aug 2000
Posts: 351
P0420 is Right Bank 3way catalyst malfunction. Have you done any mods to your car recently? If not then it's probably just the ECU needs an update. Some 2000's had parameters for the cats programmed too tight and gave false errors. This might be happening to you. Real O2 sensor failures have been rare so far in the 5th gens.
BTW, O2 sensors read the amount of free oxygen in the exhaust stream. The ECU reads this signal and determines whether you're running lean or rich.
http://www.nhtsa.dot.gov/TSBScans/sb619999.pdf
BTW, O2 sensors read the amount of free oxygen in the exhaust stream. The ECU reads this signal and determines whether you're running lean or rich.
http://www.nhtsa.dot.gov/TSBScans/sb619999.pdf
11-10-2002, 11:25 PM
#3
Senior Member
Thread Starter
Join Date: Oct 2001
Posts: 108
hey, thanks sly. i haven't done any mods so u're prolly right. i thought it was that pesky oil change timer, so i disconnected the battery to reset it. then the light came back on.
man...that's a long bulletin. guess i'll print it at work...
man...that's a long bulletin. guess i'll print it at work...
11-10-2002, 11:36 PM
#4
Senior Member
Join Date: Jun 2001
Posts: 601
Originally posted by Sly
P0420 is Right Bank 3way catalyst malfunction. Have you done any mods to your car recently? If not then it's probably just the ECU needs an update. Some 2000's had parameters for the cats programmed too tight and gave false errors. This might be happening to you. Real O2 sensor failures have been rare so far in the 5th gens.
BTW, O2 sensors read the amount of free oxygen in the exhaust stream. The ECU reads this signal and determines whether you're running lean or rich.
http://www.nhtsa.dot.gov/TSBScans/sb619999.pdf
P0420 is Right Bank 3way catalyst malfunction. Have you done any mods to your car recently? If not then it's probably just the ECU needs an update. Some 2000's had parameters for the cats programmed too tight and gave false errors. This might be happening to you. Real O2 sensor failures have been rare so far in the 5th gens.
BTW, O2 sensors read the amount of free oxygen in the exhaust stream. The ECU reads this signal and determines whether you're running lean or rich.
http://www.nhtsa.dot.gov/TSBScans/sb619999.pdf
thx
Thread
Thread Starter
Forum
Replies
Last Post
my03maxima
7th Generation Maxima (2009-2015)
9
07-28-2024 07:40 AM
TallTom
5th Generation Maxima (2000-2003)
50
07-08-2022 09:54 AM
Kyle Lee Cleveland
6th Generation Maxima (2004-2008)
1
09-28-2015 09:01 PM