O2 sensor causing bank 1 too lean?
#1
CF Junior Member
Thread Starter
Join Date: Feb 2011
Location: Salem,NH
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
O2 sensor causing bank 1 too lean?
I have a 2004 GMC SIERRA 5.3L vortec. Plugged in my Actron 9185 scanner, code is P0171 Bank 1 too lean. So I viewed engine datastream and found O2S11 v is a steady 0.000. I assume I have a bad drivers side Pre-catalytic converter O2 sensor? I also get an occasional random\multiple cylinder misfire. but I believe O2 sensor is causing this as well, Just wondering if I am right or should I troubleshoot elsewhere.
#3
CF Junior Member
Thread Starter
Join Date: Feb 2011
Location: Salem,NH
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
I did replace that O2 sensor, idle made considerable improvement. after 15 mins of idle engine light returned code isbank 1 lean intermittent, Im thinking that the pcm has to "recalibrate" for the new sensor?
#5
CF Beginner
Join Date: Jan 2011
Location: Amarillo, TX
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
It's not the o2 sensor. Granted, the sensor may have been going bad, but the bank 1 (or 2) lean codes are not caused by o2 sensors. The o2 sensor is telling the PCM that the fuel ratio is to lean. If it was somehow causing that issue, the PCM would be able to adjust it out. The ratio is to lean because either the MAF is reading incorrectly, or unmetered air is getting into the combustion chambers. So either your MAF is reading incorrectly OR you have a leak in the intake stream after the MAF.
Thread
Thread Starter
Forum
Replies
Last Post
jphurst36
2007 - 2013 (GMT900)
36
February 26th, 2024 3:23 PM