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Discussion Starter · #1 ·
This code tells me I either have a post cat o2 sensor that is bad or the catalytic converter is defective . I pulled the connector plug on the bk1 s2 ( after cat) o2 sensor checked the heater resistance ( 10 ohms ) ) reconnected and drove it for about 10 miles with no cel
. My question, a fluke or possible a dirty contact on the connector ? I would hate to think I have a bad cat .
What would you suggest as the next move it the cel p042 returns ?
 

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First of all, I think you are referring to P0420 Catalyst System Efficiency Below Threshold (Bank 1) ?
Because P042 does not exist.

I don't think you can get this code with a defective 02-sensor, well at least not without getting other codes simultaniously. So it would be a malfunctioning cat, or, something like an exhaust leak.

You will not get a cel after 10 minutes, because this is one of the "re-occurring codes", you will only get a cel if the ecu gets the code twice. So in order to get a cell, you will have to drive for a while (preferably a nice strectch of highway), turn the ignition off, and drive again. If the code reoccurs, you will get a cel).

Did you do work on the exhaust lately ? Have you removed your precats already ?
 

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P 042 is bank one sensor 3.. not on this car..

P420 is efficency low on the cat.. the Heater Circuit on the O2 Sensor has nothing to do with a 420 code..

Need to know a little more about the set up of the Car..

BUT.. if you have a Stock Configured Spyder, and are tossing a 420 code.. look for air leaks in the exhaust system.. or the cat is bad..

I've got 237K miles on my Cat.. no 420 cell yet..

Cap
 

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Discussion Starter · #5 ·
p0420 code

you are correct about the code . the code showed up from a cold start with a p0420 code i cleared it several times but it would return .
No I have done nothing on the exhaust or cat .
From what you are saying if the code returns it will make no diff to replace the post cat o2 sensor ?
 

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Yes, that's what he's saying.
 

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Check for exhaust leaks.. usually at the 'Three Amigos'.. the three bolts with the donuts under the car at the engine..

Cap
 

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Discussion Starter · #8 ·
wrong code not p0042 it was p0037 !

Blame me for being old ! I was talking to my wife and she was reading the code descriptions out of the opd book and remenbered the correct code .anyway I rechecked the heater element on the post o2 sensor . It was open ! I put a 20w 18 ohm resistor across the open heater element . I will see if this clears it up . If so I will replace the o2 sensor .
Thanks for the help and please forgive a 74 year old , my memory isn't as good as it use to be !
 
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