I have a 2018 focus st- line and the engine light came on I changed both Lamda bank one and two and the light still keeps coming on, I’ve tryed most things and a garage says it’s the cat, I’ve tryed cat clean but the light still come back on, I’ve not long had an MOT and the emissions were ok then drove a mile up the road and the light came on again, do you think it’s the cat, the car is driving ok and nice and smooth? 

Get yourself FORScan and see what codes you're getting

It first said the bank one but I changed that and it went on again and said bank two, I had it checked yesterday and the problem came up that bank two was working but the problem was in between both sensors, I was wondering if this is a common fault

I also changed bank two so both new 

16 minutes ago, Kevin sumer said:

It first said the bank one but I changed that and it went on again and said bank two,

What said it? FORScan?

I’m not sure what the computer they used but it was one that they put it was a professional one they used 

23 minutes ago, Kevin sumer said:

it was a professional one they used 

Oh dear, do you mean it was an expensive one, so it must have been good ?

No not at all or I wouldn’t have asked on here, the reasoning I’m here is to ask if this was a common fault and if so what have people done 

It is a common issue on Mk4 1.0's.  The fix is either a PCM software update or a PCM lambda learned values reset.  Unfortunately Ford don't seem to be clear on which one it is when telling the customer, who then relays it back to us.

The cats on these are also fairly poor, so that could be on it's last legs now if it's high mileage.  PCM regs are tighter than MOT regs.  But I'd definitely be trying the software routes first.

4 minutes ago, Kevin sumer said:

the reasoning I’m here is to ask if this was a common fault

Hello Kevin, you are going to have to do some testing yourself and get the Ford specific DTC's using FORScan. General purpose 'generic' code readers no matter how good, or how expensive, mostly do not read all of the Ford specific codes, and very often even misinterpret the faults.

For under £30 you can buy a vLinker FS cable, and then using a windows laptop you can download FORScan (free) and get the full picture. People here are very willing to try and help you, but we need the Ford codes so we can give you some advice.

Thank you both for this and I’ll try what you both have said, I’ve had the car a year and it had done 45000 I’ve done about 8000 and look after it  

With that mileage, it seems less likely to be the cat failing.

FORScan options:

On 4/7/2024 at 8:59 PM, unofix said:

FORScan (for use with Windows Laptop) : https://forscan.org/download.html

It's what many Ford owners use including some Ford technicians.

vLinker FS, cable for laptop: https://www.amazon.co.uk/Vgate-vLinker-Adapter-FORScan-MS-CAN/dp/B0952P4MLP

vLinker FD, for android phone: https://www.amazon.co.uk/Vgate-Bluetooth-vLinker-Scanner-Diagnostic/dp/B08H82WC8L

vLinker FD+, for iPhone: https://www.amazon.co.uk/Vgate-Bluetooth-vLinker-Scanner-Diagnostic/dp/B08H8JHWP2

 

Search Tag:   FORScan123

 

Ok thank you both for replying to me