P0130 - replaced o2 sensor - now have P0134

[SMLE]

I had a P0130 on my '03 D2, so I replaced both O2 sensors on the driver side with some cheap Chinese sensors from carparts.com. Before replacing also had misfires on the driver side, P0171 lean code and horrible gas mileage.


After replacing, ran good for 150 miles or so, now I have P0134 and P0171, but still runs smooth with no misfiring and decent gas mileage. Have put about 400 miles on it since the O2 sensor replacement.


Could the cheap Chinese sensors be causing the problems?

 

[discostew]

Of the 4 wires going to that o2 sensor 2 are for the heater. I can't remember what color those are. The other 2 wires could be your problem. One has about a half a volt on it from the ECM, this voltage is what the voltage produced from your 02 sensor is going to ride on. It's the signal wire. Each o2 sensor has a red and black wire going to it. This is a ground that is supplied internally from the ECM. I have seen a lot of trucks loose that ground in the ECM. To save money I just supply the circuit a ground at the bracket the ECM is mounted on. The system doesn't seem to care where the ground comes from it just needs to be grounded. To test the circuit for this problem I back probe that red and black wire with a t pin and ground it with a jumper wire. If you start to see activity in that o2 sensor on a scan tool with it grounded then that's your problem.

 

[squirt]

What does your O2 sensor activity look like? How about ST and LT fuel trims? Are you seeing no readings, or just bad readings?