Ford Focus problems

rodenal

Does the Focus have a post cat sensor? As P0420 can indicate a problem with this. Your holes pre-cat could also be causing an issue (if they are large enough) as the sensor will receive a different reading to what it is expecting.

As above an emissions test will point you in the best direction. It sounds like it will be the cat, but dont dismiss the post cat lambda (if it has one) - If emissions come back fine then buy yourself a spacer or a new sensor

adriandilly

atrixblue.-MFR-. wrote: »

so that one fill of 98 ron and three top ups of redX over all, from first use to last use cant see that having any impact other than the first use with 98 and injector cleaner, (98 ron has cleaning properties in it already if texaco) question i have is why did you need to use the injector cleaner in the first place have you had some issue with fuel or rough lumpy idle?

I was having crap MPG, around 26mpg, so along with changing fuel, oil, and air filters i just decided to get some redex. Its about 29-30mpg now. Doubt i'll use redex or similar again though after whats been said on here :O
Now about to ring up and book an emissions test

Hammyman

adriandilly wrote: »

On probably unrelated notes, I have an oil leak from *somewhere* which has existed before AND after changing sump pan and the rocker cover gasket. Oil has gone down very slowly (max mark to 1/4 full) since I got the car in July. I am also getting near the minimum mark for coolant..

One usually leads to the other, i.e once the coolant level gets low, the car starts eating through oil and vice versa.

adriandilly

rodenal wrote: »

Does the Focus have a post cat sensor? As P0420 can indicate a problem with this. Your holes pre-cat could also be causing an issue (if they are large enough) as the sensor will receive a different reading to what it is expecting.

As above an emissions test will point you in the best direction. It sounds like it will be the cat, but dont dismiss the post cat lambda (if it has one) - If emissions come back fine then buy yourself a spacer or a new sensor

Just been into garage and they looked at the code and immediately said pre cat lambda sensor and wanted £109 for it to be fully fitted. I asked about an emissions test and he said there's no point. They couldn't confirm whether that was the problem though, which is kinda why i wanted the emissions test. I shall be trying somewhere else tomorrow and if they can confirm which sensor it is or isn't i'll go buy one and fit myself

adriandilly

Why do we live in a world where sensors and detectors are suspected to be faulty before the thing they are actually monitoring?? You'd think they'd be designed to last longer, no?

Hammyman

adriandilly wrote: »

Why do we live in a world where sensors and detectors are suspected to be faulty before the thing they are actually monitoring?? You'd think they'd be designed to last longer, no?

Have you seen the temperatures they have to operate in? They are in the hottest part of the exhaust other than the manifold.

rodenal

Just for clarity a P0420 is bank 1, sensor 2 which is usually post cat so check they aren't spinning you a line. Wherever you take it just insist on an emmisions test as it'll only come in at about a fiver or so anyway - that way you can be sure that they are trying to tackle the right thing first!

If you get yourself a suitable lambda sensor socket for the focus you'll also find it should be pretty easy to do yourself - just get a reasonable sized extension and change it when the car is hot (obviously be very careful) - if you get into trouble soak it in penetrating spray the night before then do it whilst the car is cold.

adriandilly

rodenal wrote: »

Just for clarity a P0420 is bank 1, sensor 2 which is usually post cat so check they aren't spinning you a line. Wherever you take it just insist on an emmisions test as it'll only come in at about a fiver or so anyway - that way you can be sure that they are trying to tackle the right thing first!

If you get yourself a suitable lambda sensor socket for the focus you'll also find it should be pretty easy to do yourself - just get a reasonable sized extension and change it when the car is hot (obviously be very careful) - if you get into trouble soak it in penetrating spray the night before then do it whilst the car is cold.

That's what i thought, post cat. He said on the phone that yeah they'll do a free emissions test. But when i got there, he just went by the engine light and his little code reader. I'll go somewhere else later

adriandilly

vax2002 wrote: »

You need the Ford ovbd reader vs5 onwards
0420 is a generic obdii code, however it converts in the VBD to upv 1420/ P1420 Catalyst Temperature Sensor Failure
So the car needs an emission test to see if the cat is goosed and if that checks out a bipass on the cat sensor and replacement.
As said, the Cat looks like its given up, perhaps someone has been using a too high octane fuel or adding those snake oil injector treatments .

I've been to a few garages today and none of them seem to think an emissions test is worth while.. they say they're just for getting you through MOTs and they won't be able to tell you the exact problem. Plus they all wanted £20-£30. One girl did try and sell me Cat cleaner additive

vax2002 wrote: »

You need the Ford ovbd reader vs5 onwards

Which reader is this?, I can't find it on Google

rodenal

I can't see why they think the test isn't worthwhile - it will tell you whether the sensor is reading the correct values and the cat is gone or if ithe sensor itself is duff. Sounds to me like they are taking the code as gospel and just looking to change the sensor

Another way to check would be to check the outputs from the sensor itself, if the garage has a decent obd tool it should be able to read this without problem, you can even do it yourself with a decent digital multimeter. If the sensor is working properly you should see the voltage switching quickly when the car is warm - if it stays as a linear line that indicates a problem with the sensor.

*edit - could be an idea to look on some ford forums and see if anyone near you would be willing to run the codes through and check the lambda outputs for you. Another idea could be to ring up some mot only places and ask for the cost of an emissions test only*