Good evening all,

Happy owner of 14 plate, 100PS 1.0 Ecoboost car. I am, since about 6 months ago, the second owner and the car has done 66k miles.

About 1 month ago it threw up an Engine Management Light with no noticeable symptoms. Code read as P0420. Reset with no remedial action taken other than filling up with Shell V-power and giving it for a good long, spirited run. All remained fine for another 3+ weeks (about 250-300 miles only) before EML popped back up. Same code showing P-0420. Sadly, I have only a basic code reader so cannot monitor real time 02 sensor values.

So, now a few questions....

1) @ 66k miles is it reasonable to expect the catalyst to have 'died'? Of course, I have no knowledge of any misfires, overfuelling problems or similar that could have 'killed' it under previous ownership.

2) Would I likely be wasting my time replacing O2 sensor(s) or should I just bite the bullet and get a cat?

3) Thoughts on replacement cats...OEM @ Ford main dealer prices...gulp or (hopefully) any good steers on recommended suppliers of suitable aftermarket replacements?

4) And finally, shamefully I've not yet even had a look underneath the thing 😚 Is cat replacement a sensible DIY project on this vehicle or am I better off paying a 'proper' mechanic to do this?

Many thanks for reading, grateful for any inputs.

Cheers!

 

Get a copy of forscan a free download and a modified elm327 cable tunnelrat are the best presuming you have a laptop then you will be able to get better results.

Got the Tunnelrat ELM327 cable...and then found that my rarely used laptop has lost the ability to hold a charge 😠

Am either going to borrow a laptop or will use this one with an extension lead from house.

Any further thoughts? Especially as to whether a cat change is a sensible DIY project on this car.

Cheers!

 

I would be checking the upstream broadband sensor readings via forscan when you can . They can miss fuel and cause issues with the cat. 

Cat is easy enough to change if you end up having to replace it.

Further to this one...my friendly MOT tester told me how wonderful the car was as he moved from brake test to emissions and then spent 15 minutes scratching his head as he could not understand why the high rev emissions were SO far out of spec. Anyway, he eventually fooled the machine into giving acceptable figures and gave me the ticket but that was the final confirmation that the cat was kaput. ☹️

I invested in a new one from BM catalysts and fitted it a few weeks ago. Only iffy bit about doing the change on ramps on my driveway was that there was absolutely no way at all that the nuts/studs connecting the back end of the catalyst/downpipe to the exhaust were ever going to be undone by me laying on my back. Rusted to buggery and originally installed such that the nuts sit on the car side of the exhaust (ie accessible from above not below)  😥 rather than on the bottom side where I might have been able to get heat and more force to undo them.

Back to my mechanic/MOT guy and up on the garage lift so that between us we eventually managed to use a low profile disc cutter to hack off the studs/nuts. Then returned home to complete the replacement and all is now well. Only 'issue' being a minor rattle likely caused by a loose heatshield - due to cross-threaded (and then sheared) bolt. Leaving that for another day to see if the remains can be extracted.

On 5/3/2019 at 4:34 PM, wclark1238 said:

Further to this one...my friendly MOT tester told me how wonderful the car was as he moved from brake test to emissions and then spent 15 minutes scratching his head as he could not understand why the high rev emissions were SO far out of spec. Anyway, he eventually fooled the machine into giving acceptable figures and gave me the ticket but that was the final confirmation that the cat was kaput. ☹️

I invested in a new one from BM catalysts and fitted it a few weeks ago. Only iffy bit about doing the change on ramps on my driveway was that there was absolutely no way at all that the nuts/studs connecting the back end of the catalyst/downpipe to the exhaust were ever going to be undone by me laying on my back. Rusted to buggery and originally installed such that the nuts sit on the car side of the exhaust (ie accessible from above not below)  😥 rather than on the bottom side where I might have been able to get heat and more force to undo them.

Back to my mechanic/MOT guy and up on the garage lift so that between us we eventually managed to use a low profile disc cutter to hack off the studs/nuts. Then returned home to complete the replacement and all is now well. Only 'issue' being a minor rattle likely caused by a loose heatshield - due to cross-threaded (and then sheared) bolt. Leaving that for another day to see if the remains can be extracted.

Hi, apart from the rusty bolt, easy to remove and install?

I have exactly the same problem as yours with the same code. Cleared code and used Cataclean and it was good for nearly 1k miles before the light came again with the same code.

I’m thinking of using a BM cat as well… are they good?

2 hours ago, gentil79 said:

Hi, apart from the rusty bolt, easy to remove and install?

I have exactly the same problem as yours with the same code. Cleared code and used Cataclean and it was good for nearly 1k miles before the light came again with the same code.

I’m thinking of using a BM cat as well… are they good?

This tread has been dead for 2 years, @wclark1238 has not been on the forum since 5th March so he's not a regular daily or even weekly visitor.

Ok, thank you.

Hello, 

I have this same error code on my vehicle, (ford focus 1.0 ecoboost 125, 2014). 

Catalyst System Efficiency below threshold bank 1
P0420
$07e8pd

Can someone advise which lambda sensor this is. 

Is it this one? 

PRE-CAT FRONT UPSTREAM LAMBDA OXYGEN O2 SENSOR PROBE 
SENSOR LENGTH 688MM - 6 PIN CONNECTOR - 5 WIRES 

Thank you

I think it would be the post cat, but as I found I my wife’s car, it was the Cat itself that was faulty, not the sensor. The cat on these cars have a tendency to fail more that the sensors

We have had a quote to replace £1120 is that about right?

The catalytic converter itself is approximately £800 from Ford. Required gaskets and consumables will cost approximately £20 and the remaining £300 for labor.

For a job performed with OEM parts that price sounds about right to me.