2016 Ford Fiesta 1.0 Ecoboost Titanium - Oxygen Sensor

[cedrica]

Hi Andy
My engine light as come on and I have realized that this could be dirty fuel that is causing the problem. Ran a diagnostic on the car and the error is "O2(Oxygen Sensor) Sensor Signal Stuck Rich - Bank 1, Sensor 1" is there a way to clean this sensor without removing it.

Many thanks
Cedric

 

[tabijan]

P2196 is usually a failed rather than dirty sensor. It’s unlikely any fuel system cleaner poured into the fuel tank will restore sensor function. If you’re going through the trouble of removing the sensor, have a new one ready to install. IIRC, the 1.0 upstream sensor is as easy as an oxygen sensor is to replace. I don’t know how sensitive Fords are but budget sensors can cause problems in other cars. Motorcraft or direct fit Bosch or Denso from a reputable source. Lots of fakes out there.

Hopefully P0420 doesn’t reflect permanent damage to the cat. Then hopefully the situation was caused by a faulty sensor. Otherwise there’s more work to sort the rich running condition when there’s a functioning sensor in place to guide further diagnostics.

Sixto
2013 SE 1.6 hatchback 135K miles

 

[Handy Andy]

You also have to look into - if the P-420 condition persists - in having to replace that catalyst - many times from feedback in shops - the P0420 fail actually comes from the blocking occurring in the media of the catalyst pipe housing that honeycomb - it's plugged - that happens before it sets the P0420 because of the sensor upstream got smacked with debris from it failing - the deceleration you have done in ordinary driving closes off the intakes' throttle plate - but air can still arrive to the engine as engine braking - thru the tailpipe - and if the catalyst failed - that carbon and soot from it can get sucked back into the motor and that is thru where that sensor is mounted the exhaust manifold.

Since it gets so hot back there - it can fuse this onto the sensor and it's media too...

So if you can, monitor that vacuum in the intake manifold after replacing that sensor - a clean exhaust (non restricted) one lets the engine show 20in Hg at idle and as you drive 35MPH on to about 50MPH will be around 15~18 in Hg on regular smooth open pavement no hills.

It's when the manifold vacuum drops excessively and the engine acts sluggish and seems to be under more of a load that normal, you may have more work ahead of you due to the damaged pipe and the possibility of the plugging that goes with it.