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Error Code P0420

  #16  
Old 04-30-2007, 09:23 PM
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sure, switch bank 1 and bank 2 post cat sensors, see if the code follows the cat or the sensor. its not a lot of work, but if you cant use a ford scan tool its about the only thing left. youre gonna have to clear the code and see how it comes back, disconnect the battery or have autozone clear it. not to knock on the autozone or advance or checker guys or anything, but they dont get the same traning a technician does, ask the experts.
 
  #17  
Old 05-01-2007, 06:13 AM
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My "expert" is out turkey hunting right now That's main reason why I asked here, I knew I would get the help I needed by people here. So take the sensor after the cat on both sides out and switch them, reset the code, and if it switches to bank 2 then it's the sensor. If it stays bank 1 it'll be the cat. Is that correct?
 
  #18  
Old 05-01-2007, 02:28 PM
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99.9% of the parts people at AZ are idiots. The only training they have is how to sell you a part even if you don't need it. I'm surprised they didn't try to sell you a set of four O2 sensors to fix your cat.

You either need a cat or you have an exhaust leak upstream of it that is sucking air in. O2 sensors don't cause this code.

The only way to test the cat is to compare the reading of the up and downstream O2 sensors with a multi channel lab scope, graphing multimeter, or scanner.
 
  #19  
Old 05-01-2007, 04:19 PM
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Alright, I'll have my Uncle check the readings, he's done this before. Now with it the way it is will it be okay to drive to Kansas and back?
 
  #20  
Old 05-02-2007, 06:46 PM
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I forgot to ask this earlier, which side is Bank 1? Also how would I know what cat I need? I've found some that are oval, round, and oval w/ air tube. Might as well go ahead and start pricing them out just in case. My pipes are 2 1/5"
 
  #21  
Old 05-02-2007, 08:22 PM
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bank one is the passengerside. As long as it isn't clogged, it's ok to drive this way. Most exhaust shops can do a pressure test to see if it is clogging up.
 
  #22  
Old 05-03-2007, 06:41 AM
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Alright, thank you. As long as the weather is nice after work today I'm going to switch the O2 sensors to see if it kicks the error code to bank 2 or if it stays at bank 1.
 
  #23  
Old 05-03-2007, 02:13 PM
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  #24  
Old 05-03-2007, 03:41 PM
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Is that what allows me to remove my cats and not have the SES light on 24/7 or do I still need my cats on? If I can remove them I will.
 
  #25  
Old 05-03-2007, 07:01 PM
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P.E. sells these for Mustang owners that installed the off road pipes, eliminating the cats ........ technically for off-road applications ...... I put 60K+ miles on my Interceptor after installing the MIL's with no problems ....... 60K off-road miles ..........
 
  #26  
Old 05-03-2007, 07:55 PM
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I'll definitely have to check those out. I'm just a little curious as to where they hook up to aside from the rear O2 sensor.
 
  #27  
Old 05-03-2007, 08:26 PM
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They splice into the rear O2 sensors. You'll need to weld a bung into your new straight pipe and install the sensor into it. Call them, they're great on customer service.
 
  #28  
Old 05-03-2007, 11:02 PM
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if your catalyst has low efficiency it could plug up and cause your truck to run like total crap at any moment. if it was sucking in air you would have a lean code, which you dont. its either the cat or the sensor. dont let yourself get side tracked here. The governement says that auto makers have to warranty cats up to 80000 miles. but not the labor, beyond that its your mess. Or you could just keep driving it, the only reason the check engine light is on is beacuase you are potentially polluting with a failing cat, half of the requirements of OBD 2 are emissions related, and like 90% of all Powertrain DTC's are emissions related too. its a long story, but in short get a new cat or get a new sensor. as long as the bolts arent completely rusted you should be able to get them off with air tools, maybe hand tools. if they are super rusty=torch.
 
  #29  
Old 05-04-2007, 06:13 AM
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Yeah mine has 98,000 on it. I'm a little over the 80,000 mile point. Weather was chilly last night so I wasn't able to get out there and switch the O2 sensors around, so I'll try that this weekend, it's supposed to be nice.
 
  #30  
Old 05-04-2007, 07:41 AM
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Not really, you need to monitor the o2 sensors and see if the rear o2 sensors follow the fronts. If they do, the o2 sensors are ok and the cats are no good.
 

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