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Bought a cheap code reader that gave me a ghost P0420 on a perfectly good cat

It sent me down a two hour diagnostic rabbit hole on a 2015 Civic, chasing a problem that wasn't there. What's your go-to scanner for quick, reliable codes?
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4 Comments
shane_park92
shane_park9215d agoMost Upvoted
Wait, you're telling me the battery voltage can actually mess with those cheap readers? I never even considered that. That's wild. Now I'm sitting here thinking about all the codes I might have chased for no reason over the years. I had a cheap one give me a random misfire code once on my old Corolla and I replaced spark plugs and coils for nothing. Makes me wonder if my battery was just being moody that day. I'm honestly shocked I never put that together.
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ryanm60
ryanm602mo ago
Got a BlueDriver too, never fails me.
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jamesf29
jamesf292mo ago
BlueDriver for me, never had a false code.
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spencer400
spencer4002mo ago
Ever think about how the car's battery voltage can mess with cheap readers? A low or dirty power signal can make them spit out junk data like that ghost code. I always check the battery health first before I even trust what the scanner says.
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