Innova 3100 codes manual

SOURCE: my check engine light came on 2004 ford taurus had

P174 means Oxygen sensor was slow in switching Single, Right or Rear HO2S - Fuel control

P171 means Oxygen sensor not switching - system was at adaptive limits - Single, Right or Rear HO2S - Fuel control

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SOURCE: po443 code 2002 ford taurus

That code is for the Evaporative Emissions. It could be a bad Evaporative Emissions Canister Valve or just a bad vacuum line or my granddaughter's 1997 Ford Escort had that code and her gas cap was NOT on. Now when you figure out what one it is disconnect the battery for 10 minutes to reset the computer.

SOURCE: 2004 ford Taurus misfire code upon startup

does the engine miss fire when running if not check the cam and crank sensor may have small crack but always check coil packs wires and plugs fuel injector first

SOURCE: Check engine light on P420 code 2004 Matrix

PO420 is a Catalyst Efficiency Beloe Threshold (Bank 1)
I'd go to AutoZone or your auto parts store to get a printout of the possible fixes to this problem.

Hope this helps...

SOURCE: 1996 taurus p420 code

The P0420 means Catalyst System Efficiency Below Threshold (Bank 1), and the P0430 means Catalyst System Efficiency Below Threshold (Bank 2).
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