Hi all,

I've looked at some live readings on ForScan to assess a P0420 code that popped up. To my untrained eye, everything looks fine, bar the 02 Bank1 Sensor 2 giving near on identical reading to 02 Bank1 Sensor 1. While they are neither 02 are switching between rich and lean as quickly as I like, I don't know if I'm expecting too much here from my 2009 Focus engine. 

The MAF sensor is rising with the revs, as I believe to be expected.

The MAP sensor decreases with rpm, as I believe to be expected. 

Fuel trim looks fine, rises with revs with the top end around 10%, as I believe is normal.

Braking results in both sensors to switch to lean, as I believe is normal. 

I'm simply trying to exclude any other possibilities before I start looking at a new cat. Any nudges in the possible right direction would be a big help. Does anything look out of the ordinary from the data?

 

 

Have a look at the Mode 6 Test results in FORScan, the results might not mean anything other than confirming that the Cat is past its best.

20 minutes ago, Tizer said:

other than confirming that the Cat is past its best.

Very true !!

Your average cat only comes with 9 lives and a 2009 cat is well past it's expiry time 🤣

36 minutes ago, unofix said:

Very true !!

Your average cat only comes with 9 lives and a 2009 cat is well past it's expiry time 🤣

@unofix @Tizer 😂most appreciated lads, worth a laugh while i'm feline so down. 

Bar the bad cat which I was half expecting, do all the other sensors look within their typical ranges? I wouldn't want to replace the cat and the origin of the issue still exists, or is it simply just a matter of shes had her day and i need a new converter? with new 02sensors?

I would have a look at the Mode 6 Tests before making any decisions.

Check the cat temps. I'm in the same scenario. Might try to clean it first tbh. I fixed a ground and a half under my battery and the battery to chassis ground.. the code went away lol. I'd check your circuts for the o2 sensors make sure you don't have a similar issue

 I have 2013 2.0 na mtx75. The grounds on this car are literally the worst excuse for ground I have ever seen in my life EVEN WHEN I WAS TEACHING 19 YEAR OLDS WHAT A SCHEMATIC IS WAS, AND HOW TO CREATE A BASIC DC CIRCUT, HAD  DISPLAY OF BETTER GROUNDING 😆 . 

10 hours ago, FUKASS9000_SE said:

Check the cat temps. I'm in the same scenario. Might try to clean it first tbh. I fixed a ground and a half under my battery and the battery to chassis ground.. the code went away lol. I'd check your circuts for the o2 sensors make sure you don't have a similar issue

 I have 2013 2.0 na mtx75. The grounds on this car are literally the worst excuse for ground I have ever seen in my life EVEN WHEN I WAS TEACHING 19 YEAR OLDS WHAT A SCHEMATIC IS WAS, AND HOW TO CREATE A BASIC DC CIRCUT, HAD  DISPLAY OF BETTER GROUNDING 😆 . 

Cheers, I really appreciate the info. I've read a few times how a dodgy earth can play all sorts of havoc with this car. The battery to chassis ground has definitely seen better days on my motor, connection is still strong but I must confess I was tempted to change the battery earthing strap/bolt. With this being said the resistance at the 02 sensors look well within parameters from the Module6 test, and would indicate a decent connection? I believe...

"Fixed a ground and a half under your battery", sorry but could you clarify this a bit. As in the 02 sensor earths to the connection? 

As for giving it a clean, I've a bottle of Cataclean ready to be put in a quarter tank of petrol to be Rev'd out to Red in all gears for a decent motorway run 60mph+, I'm hoping this will help as I've definitely noticed a drop in MPG, although also know the MPG is not an accurate read. Failing this all and I need to fit a new Cat, I've heard that its important to reset the EGR and run engine at idle for 5 minutes and the 2000rpm for 2 minutes, then switch the engine off so it can relearn the new cat in the system and its values.

 

@Tizer @unofix @FUKASS9000_SE Possibly you gents might be able to make better sense of the readings I got from the Module6 test, a couple things in red were highlighted  them being;

Oxygen Sensor Bank 1 Sensor 2: Time to reach 30-60C in Oxygen concentration during - MID 2 - TID 91 - Value 0.0mV (Highlighted in RED)

Catalyst Bank 1: Diesel Oxidation Catalyst Exotherm Efficiency During Regen - MID 21 - TID 90 - Value 0.803 (Highlighted in RED) 

 

//

(OK) [14:19:41.556] Mode 6 - Test Results for Specific Monitored Systems has been started
(OK) [14:19:41.592] Misfire monitoring: Complete
(OK) [14:19:41.593] Fuel system monitoring: Complete
(WARN) [14:19:41.595] Comprehensive component monitoring: Incomplete
(WARN) [14:19:41.597] Catalyst monitoring : Incomplete
(OK) [14:19:41.598] Oxygen sensor monitoring: Complete
(OK) [14:19:41.600] Oxygen sensor heater monitoring: Complete
(OK) [14:19:41.732] Test completed successfully, no errors found

===OBDII Mode 6 Results====

[Oxygen Sensor Bank 1 Sensor 1]

Rich to lean sensor threshold voltage (constant)
MID: 1
TID: 1
Value: 351.4 mV
Min: 351.4 mV
Max: 351.4 mV

Lean to Rich Sensor Threshold Voltage (constant)
MID: 1
TID: 2
Value: 507.5 mV
Min: 507.5 mV
Max: 507.5 mV

Low sensor voltage for switch time calculation (constant)
MID: 1
TID: 3
Value: 190.3 mV
Min: 0.0 mV
Max: 7995.3 mV

High sensor voltage for switch time calculation (constant)
MID: 1
TID: 4
Value: 639.3 mV
Min: 0.0 mV
Max: 7995.3 mV

Rich to lean sensor switch time (calculated)
MID: 1
TID: 5
Value: 60 ms
Min: 0 ms
Max: 370 ms

Lean to rich sensor switch time
MID: 1
TID: 6
Value: 30 ms
Min: 0 ms
Max: 230 ms

Time to Reach 30% Rise in Oxygen Concentration During Coast-down
MID: 1
TID: 90
Value: 0.156 :1
Min: 0.000 :1
Max: 1.008 :1

Time to Reach 30-60% Rise in Oxygen Concentration During Coast-down
MID: 1
TID: 91
Value: 0.141 :1
Min: 0.000 :1
Max: 1.008 :1

Time to Reach 60% Rise in Oxygen Concentration During Coast-down
MID: 1
TID: 92
Value: 100 ms
Min: 0 ms
Max: 25000 ms

Oxygen Concentration Error During Full Engine Load Condition
MID: 1
TID: 93
Value: 880 ms
Min: 0 ms
Max: 2090 ms

[Oxygen Sensor Bank 1 Sensor 2]

Time to Reach 30% Rise in Oxygen Concentration During Coast-down
MID: 2
TID: 90
Value: 0.039 :1
Min: 0.000 :1
Max: 1.004 :1

Time to Reach 30-60% Rise in Oxygen Concentration During Coast-down
MID: 2
TID: 91
Value: 0.0 mV
Min: 48.8 mV
Max: 7995.3 mV

[Catalyst Bank 1]

Diesel Oxidation Catalyst Exotherm Efficiency During Regeneration
MID: 21
TID: 90
Value: 0.803
Min: 0.000
Max: 0.756

[Oxygen Sensor Heater Bank 1 Sensor 1]

Heater Impedance
MID: 41
TID: 90
Value: 113 Ω
Min: 0 Ω
Max: 1700 Ω

[Oxygen Sensor Heater Bank 1 Sensor 2]

Heater Impedance
MID: 42
TID: 90
Value: 151 Ω
Min: 0 Ω
Max: 2500 Ω
===END OBDII Mode 6 Results====

 

 

 

 

 

I'm no expert but my interpretation is that the Cat is past its best and the failure in one of the Tests for the Rear Sensor was because of the Cat being poor rather than a problem with the Sensor. 

6 minutes ago, Tizer said:

I'm no expert but my interpretation is that the Cat is past its best and the failure in one of the Tests for the Rear Sensor was because of the Cat being poor rather than a problem with the Sensor. 

Yeah I figured the same, given the switching of both 02's albeit not fast at all, they do show operation. I'm gonna give it a long motorway blast with Cataclean in the tank and we'll see what happens.

I opened the bonnet to topup some windscreen wiper fluid, after a little gander while I was there, this has led to my likely refitting of a catalytic converter, typical. 

In the event I do change the cat, does anyone have any good recommendations on where I could get one? Or what to avoid, or look for etc. 

I wrote up some notes in the event I do change it, any tips or pointing out any redundant steps would be a great help. 



Catalytic converter replacement:

- Jack car up 

- Remove EGR relay from fuse box 

- Disconnect negative from battery 

- Disconnect 02sensors connection clips x2 (push in tab pull out connection)

- Remove windscreen wipers x 2 (15mm) and scuttle panel (Torx30)

- Remove cross section under rocker cover (10mm) x 2 bolts

- Remove o2 sensors (22mm) x 2 sensors, if accessible and necessary at this point. 

- Remove heat shield (10mm bolts) x 4 bolts, and remove if able to do so at this stage.

- Go under car and unbolt 2 x 10mm bolts on underside of catalytic converter bracket

- Go further back under car near the flexi pipe, unbolt the retaining bracket (10mm) x 2 bolts 

- Undo 2 x exhaust flange nuts (15mm)

- Come out from under the car and remove bolts from exhaust manifold to cylinder head (engine) (15mm socket) x 5 bolts 

- Jack up under engine and Unbolt engine mount bolts (15mm), located SouthWest of the engine and SouthEast of the Coolant tank (facing the car).   

- Ratchet left side of engine (facing engine) back with strap to chassis, for enough clearance to remove the old Catalytic Converter.

- Clean engine manifold, fit seals and replace with new Cat.  

- Refit all in reverse 

- Reset ECM/EGR?, and run the car at idle for 5 minutes and at 2000rpm for 2 minutes then turn the car off. This is so the computer can learn the new values of the new catalytic converter.
 

There is nothing more to be said, no more tests to run and no more results need to be checked. The catalytic converter has gone to that big scrap heap in the sky. 🙁

No amount of cleaning or bottles of snake oil is going to bring it back, its an ex-parrot, sorry I mean an ex-cat.

Worth looking here to see what they offer?:
https://www.bmcatalysts.co.uk/

20 hours ago, unofix said:

There is nothing more to be said, no more tests to run and no more results need to be checked. The catalytic converter has gone to that big scrap heap in the sky. 🙁

No amount of cleaning or bottles of snake oil is going to bring it back, its an ex-parrot, sorry I mean an ex-cat.

Yurrrrpp! Sounds like she’s gone! Will look into buying and refitting another. 
 

Also, I’m now noticing a considerable drop in Mpg, as such I’m driving 3-4 miles and it’s dropping 10 miles on the on screen miles left in the tank. Is this typical of a failed cat? 

19 hours ago, Shearers said:

Worth looking here to see what they offer?:
https://www.bmcatalysts.co.uk/

Cheers buddy I’ll look into this

1 hour ago, EastLondonLiving said:

Is this typical of a failed cat? 

Very much so. Exhaust gas is causing back pressure in the manifold.

1 minute ago, unofix said:

Very much so. Exhaust gas is causing back pressure in the manifold.

Thanks for the reply @unofix this makes sense.  I don’t know if it has any connection, but while under the hood, I noticed a small diameter (>10mm) hose that was running to nowhere, coming out from high on the firewall. I assume this must have popped off from somewhere, yet no idea what it is. 

Kindly in your wisdom, could you identify what this is for me? And where it is even meant to be going? ….I gather this would have very little to do with my Cat issues so to speak? 
 

5 minutes ago, EastLondonLiving said:

but while under the hood,

NO !!

15 minutes ago, unofix said:

NO !!

Was the no to all the questions? 🤣

Cant find a diagram for under the bonnet for the life of me. Thanks all the same 

The "No" was in response to the use of American Automobile mumbo jumbo.

So in answer to the question of what you found under the bonnet, it is likely just a drain or vent pipe, but I'm sure @TomsFocus will know the answer 👍

26 minutes ago, unofix said:

The "No" was in response to the use of American Automobile mumbo jumbo.

So in answer to the question of what you found under the bonnet, it is likely just a drain or vent pipe, but I'm sure @TomsFocus will know the answer 👍

That’s I really appreciated. Forgive the Yankee lingo haha I just wanted to be cool today, epic fail. 

As for the Americans, they do have a lot more accessible info online for their Ford motors, in terms of diagrams however completely different configurations of engines etc, albeit a little help. 
 

Quite relieved to read you identify as possible drain or vent, and can essentially be left be. And not a failed vacuum hose of some sort. Thanks buddy 

That's the scuttle drain.  Stops your wiper motor sitting in a pool of rain water.

(PS - CV axle is also an Americanism.  Driveshaft is the correct term over here.)

1 minute ago, TomsFocus said:

That's the scuttle drain.  Stops your wiper motor sitting in a pool of rain water.

(PS - CV axle is also an Americanism.  Driveshaft is the correct term over here.)

That makes perfect sense thanks @TomsFocus

By the time I’d realised my incorrect term for driveshaft it was too late, but please excuse the novice-ry

Ok so no beating around the bush…she said 

Im going to need to replace the Cat, I can’t be driving 5 miles for every 10 burnt. I’ve narrowed it down to this spec Ford 1855297 / BM92132H, I think this looks all about right. 
 

 

Prices range from £70-700, I understand you get what you pay for. How long roughly would a £200 converter last say, average 5k miles a year? 
 

Would it be wise to just buy some new o2 sensors while I’m at it? Or replace with the old ones? Any suggestions on decent (not too sensitive/ problematic) aftermarket o2 sensors, let me know.

Aftermarket O2 sensors are often crap.  I'd keep the originals unless they are proven faulty.

Have you checked the cat on your car btw?  There was a twin cat setup for some of the 1.6 Mk2 Focus's which is much more expensive.

7 hours ago, TomsFocus said:

Aftermarket O2 sensors are often crap.  I'd keep the originals unless they are proven faulty.

Have you checked the cat on your car btw?  There was a twin cat setup for some of the 1.6 Mk2 Focus's which is much more expensive.

Yeah fair enough, I’ll fit the old o2s to the new cat. 
 

I had given it a brief look over, looks very much like the one in the picture above. I searched my VIN number and it came up with the fitable car parts, in this case the cat number Ford 1855297. I sure do hope it’s the correct one. 

Where was the twin cat positioned?