ok i have got the codes and it seems to be the o2 sensors. but how do i figure out which one it is. my 2001 dakota with 3.9l has 4 of them. in order the codes are p0031 p0051 p0132 p0152 p0138 p0136. from the code list it says bank 1 sensor 1 for 0031, where is bank 1? and which one is sensor one? 0051 is b2s2. 132 is b1s1. 152 b2s1. 138 b1s2, 136 b1s2. it has 2 newer sensors in it but if i have to i will replace them all again.

 

fixed it with a new truck

 

haha thats always a good fix.

 

Bank 1 is driver side downpipe/exhuast manifold.

Bank 2 is passanger side downpipe/exhuast manifold.

you have 4x 02s, with 3 cats more then likley, 2 pre cats and one after them.

B1/S1 = Before Driver Side Cat (closest to the motor)

B1/S2 = After Driver Side Cat (farthest away from motor)

B2/S1 = Before Passanger Side Cat (clostest to motor)

B2/S2 = After Passanger Side Cat (farthest away from motor)

o2s useally need to be replaced within 50-70k miles, and since you have 4 its bit expensive, each one is about ~50$ so thats 200 for new sensors. Have fun.