Engine management light on
2004 Ford Fiesta 1.4 zetec petrol

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buzby
Driver
6 points

Problem added: Jan 5, 2012 (9 years ago)
engine management light is on.diagnosis reads catalyst efficiency below threshold[bank 1]P0420.any ideas

Car details
Car: Ford Fiesta
Variant: 1.4 zetec petrol
Model Year: 2004
Category: Electrics, ECU, Warnings & Lights
Replies and Fixes
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autoinsider
Top Fixer
939 points

Jan 6, 2012 (9 years ago)
The catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream O2 sensor reading should be fairly steady. Typically the P0420 code triggers the Check Engine Light if the readings of the two sensors are similar. This is indicative of (among other things) a converter that is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.


Source: http://www.obd-codes.com/p0420
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buzby
Driver
6 points

Jan 7, 2012 (9 years ago)
so p0420 could be cat replaced or just a sensor or both?
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rizzo
Top Fixer
388 points

Jan 7, 2012 (9 years ago)
it could be the cat or it could be a lambda ideally you need to get the live data read via computor to see what the engine is doing
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buzby
Driver
6 points

Jan 9, 2012 (9 years ago)
how much about would fords charge for this

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