O2 Sensor Swap Guide: DIY Fix For Better MPG

Had the exact same issue on my 2020 Chevy Silverado diesel last month. The check engine light came on and fuel efficiency dropped noticeably, was burning through diesel way faster than normal. Diagnostic confirmed a faulty oxygen sensor, but the real problem was deeper. Found corroded wiring harness connections near the exhaust system that were causing sensor misreadings. These bad connections were making the engine run rich, which was overworking the catalytic converter. Tried the DIY route first but accessing those connections properly required lifting the truck. A pro mechanic found additional wear on related components that wouldn't have been obvious to the untrained eye. This isn't a quick sensor swap job, proper diagnosis and repair of the wiring is crucial to prevent future issues. The oxygen sensor serves a vital role in engine performance and emissions control. Would strongly recommend having a certified mechanic handle this one. Not a catastrophic problem if fixed promptly, but ignoring it risks damage to your catalytic converter and continued poor fuel economy.

Had the same oxygen sensor problem with my DMax last year. The exhaust sensor was throwing codes and killing my fuel efficiency. My air-fuel ratio was all over the place. Got it fixed at a shop after my DIY attempt didn't work out, the automotive sensor was a pain to access without a lift. Final bill came to around €400 including parts and labor, plus they spotted and fixed some corroded wiring while they were in there. Have you been able to get it sorted yet? Curious what they charged you and if you've had any other issues pop up since the repair. These sensor problems can sometimes be a sign of other stuff going wrong.

Got mine all sorted now, turned out simpler than expected. After seeing the mechanic, they diagnosed it as just a connection issue with the O2 sensor. The wiring plug had worked loose and developed a bad connection, which was throwing off the air-fuel ratio readings. Total repair was 95€ to fix the cable and clean up the connection point. Much better than the full sensor replacement I was worried about! Since the fix, fuel economy is back to normal and the check engine light has stayed off. The exhaust system is running clean again too. The mechanic showed me that when these oxygen sensors act up, it's often just connection issues rather than the sensor itself being bad. Could've been worse, if left too long these problems can mess with the catalytic converter. Definitely worth getting it checked out early when you notice the symptoms. Sounds like you paid more because you needed the full sensor replacement plus wiring work. Guess I lucked out with just needing the connection fixed. The key is catching these issues before they cause bigger problems in the exhaust system.

Thanks everyone for the advice. Finally got this sorted out yesterday. After getting burned by my last mechanic, I found a reputable diesel specialist with good reviews. The check engine light issue turned out to be both the oxygen sensor and some damaged wiring. They found the connections had corroded from water exposure. Total bill came to €375, €150 for the O2 sensor, €175 for labor, and €50 for the wiring repair. Really glad I didn't try tackling this myself. The mechanic showed me how the sensor was tucked behind several components, and accessing it properly required putting the truck on a lift. They also cleaned up some grime around the catalytic converter while they were down there. Car maintenance costs sting, but my fuel economy is already way better. The check engine light is off and she's running smooth again. Definitely learned my lesson about addressing these automotive sensor issues quickly before they cause bigger problems.