Hello like the title said I'm having that code. When it first came on. I took it to a mechanic and change the Catalytic Converter not just once but twice. I got tired of that shop (personal reason) so I started to work on it more myself. it rarely show it up. lately its started to show up more. so I Change both Banks on the car. and it still show up. Also its a Ford Fusion 2016 S 2.5 litter. I even told people took that I think I hit something on the road before it show up. but nobody believes me at this point. I'm Lost right now and I have a few months left tell I have to do a State Inception on the car. I don't know where to turn to. Also too its turn itself on and off once in a while too.
Since you said it happened after you hit something , you may have damaged the wiring or harness of the o2 sensor. I would look there, if that isn't it trouble shot the o2 sensors itself. I have a feeling your sensor is either bad or it's a damaged wire.
You said it turns on by itself too. Does your car have remote start. If yes you might be activating it with out realizing it. My 2000 Honda crv used to turn on by itself and I didn't know why. It turns out it the original
owner installed remote start installed and if you hit lock and unlock it with turn on . It may have it and you don't even know it.
If it has remote start the unit maybe defective. Another possibility is you have a issue with ecm , another component or wiring. Electrical really isn't my thing but someone else will jump in who is alot more knowledgeable then me with electrical
Just because there is a code for p0420 it doesn't mean the cat is bad. There are over dozen different things that can throw this code and proper diagnosis is the only way to know for sure.
Even if your cat is bad and you replace it, you still have to find out what caused it to go bad in the first place if there is one.. If you don't find the underlying cause it could bad again.
For future reference remember, just because there is a code it doesn't mean that part or sensor is bad. You should diagnose it first to confirm that component is indeed faulty.
When it first came on. I took it to a mechanic and change the Catalytic Converter
Why did you do that? Didn't you investigate the other possible causes of that code? As @nissanrob88 points out it could well be damaged wiring.
so i took it to a shop first and they said that. even when i went to autozone it pull up that code to change.
Hello like the title said I'm having that code. When it first came on. I took it to a mechanic and change the Catalytic Converter not just once but twice
Sounds like this shop put you through the ringer not once, but twice. Other than the original cats being welded, they're apparently just parts changers. They're not real mechanics if they shotgun parts and hope that fixes it. I'm with @chucktobias and @Nissanrob88, your 02 sensors are probably damaged, or the wiring itself is damaged after you basically bottoming out. You might want to check those.
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