Code P0157

MATTHEW05

MEMBER
2004 DODGE RAM
5.7L
V8
4WD
AUTOMATIC
140,000 MILES

Hi, I drive the truck listed above 1500. I’m receiving a P0157 code on my reader. My STFT B1 and STFT B2 is “-0.8 to 0”, which I’m pretty sure is normal. On the other hand, my LTFT B1 has a fixed 3.1%, and my LTFT B2 has a fixed 3.9%. I’m not really sure what this means, but am I going to have to replace some o2 sensors? It’s affecting my driving, when I come to a semi-aggressive stop, my truck will shut down. Really annoying when stopping in traffic. Also a constant check engine light.

1 Reply

JIS001

MECHANIC
3,408 POSTS

Hi, your fuel trims are perfect. As a rule of thumb most manufacturers allow 10% plus or minus total but the check engine light will not light up for trims unless your over or under 30%.. What your code indicates is the your oxygen sensor circuit reading is low. So it sounds like you could have a faulty 02 sensor.

Here is a link on how to test and replace sensor:

https://www.2carpros.com/articles/how-to-test-an-oxygen-sensor-02-sensor

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

I have found it easy to replace the sensor without damaging the threads when the exhaust is hot. But I have been doing this for a while and as the link will suggest, wear protective clothing. Hope the links are useful and please update us with the results.