Check engine light p0135 and p0137 volvo s70

[Randall0208]

Hello, I recently bought this year 2000 volvo s70 non turbo. The next day I got a check engine light for codes p0135 and p0137. I did some research and it's something to do with the o2 sensors. I looked up how to test a o2 sensor with a multimeter and my upstream o2 sensor wasn't giving any conduince whilst the other one was. I thought the o2 sensor must be shot so I replaced it with a $50 one I picked up on amazon. It was an upstream o2 sensor and said it's compatible with a 2000 volvo s70 so I bought it because the oem ones were upwards of $200. After replacing it theres no difference, still have the check engine light and same codes after replacing it. My gas milage hasn't gone down at all really, I'm supposed to get 26 on highway and I drove on the highway for about 40 min and had 24 mpg and it was taking in account the city driving I did too to get to the highway. I'm guessing maybe it's a vacuum leak? It idles fine and runs fine never stalls out. If anyone knows any information please let me know. I did read some article where people had the same problem as me and after replacing their o2 sensors the code wouldn't go away and they said it was a computer problem and the computer didn't want to let go of that code for some reason? Please help!

Edit: I believe it was this o2 sensor I ordered: ECCPP air fuel ratio sensor (I would put the link but it wont let me)


I compared the wires, the sensor itself, and everything the connector went in fine everything was the same.