Hi!
I have a 2005 Fiesta ST with
full milltek system with high flow cat
and K&N filter and cosworth cams

I'm getting these DTC's from my car

P0136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

I have just bought this to solve this problem but nothing happened
http://www.teamtorquesteer.co.uk/category-152/205-04.html
I still get the same DTC's

Please help me!

think Pinkrinse is properly the best person to ask for those question!

you rang?

Yeh my MIL elimintaor didnt work either and I still have my engine light on (its on & off like twinkling fairy lights). I had a friendly Ford tech replace various sensors (front oxygen sensor and TPM sensor I think?) on my car (under warranty ahem...) and that still didnt solve it. I dont know if you want to try having these sensors looked at and replaced (I dont know how much that costs in Finland).

If you've got a sports cat fitted then the emissions system is still standard so both HEGOs should work.

The reason you've got the MIL on is because you've got a problem with one of them, the rear (post cat) one in fact.

How long has this been on, can you think what has been done to may have caused it??

A trip to a sympathetic dealer MAY get you sorted or even getting the AA out to turn it off for you may sort it as well.

As dave has said looks like you got a problem with your rear oxgen sensor (the one after the cat)check to make sure they have fitted it or reconnected it after fitting your miltek system.For the fault codes you have it looks like its not connected .

It's a great job we got people like all you nerds on the board

Got rid of my mil eliminator and now I only get the DTC P0141

I don't know how technical you are but the following site might help you: http://www.bba-reman.com/content.aspx?content=NEXT_DTC_P0141

The following is taken from the Ford ETIS but I doubt it is the alternator:

5306 - FIESTA ST - MIL ON DUE TO DTC P0141
SOME FIESTA ST VEHICLES BUILD BETWEEN 01.03.05 AND 30.09.05 MAY EXHIBIT
A MIL ON
CONDITION WITH DTC P0141 PRESENT, CAUSED BY AN INTERMITTANT ALTERNATOR
ISSUE. TO
CHECK, IF THIS IS AN INTERMITTANT ALTERNATOR ISSUE OR A REAL FAULTY
DOWNSTREAM
HEGO, DO THE FOLLOWING CHECK. 1) DELETE ALL DTC'S.2)CHECK THE BATTERY
VOLTAGE AT
IDLE, IF <13 VOLTS, EXCHANGE THE ALTERNATOR.3)CHECK BATTERY CONDITION
AT KEYOFF,
IF <13 VOLTS, RECHARGE THE BATTERY.4)WITH THE BATTERY NOW RUNNING ABOVE
13 VOLTS
, WARM THE ENGINE UP TO A COOLANT TEMPERATURE ABOVE 60°C. 5) KEY OFF,
START THE
ENGINE AGAIN AND IDLE FOR 60 SECONDS.6) REPEAT STEP 5. 7)IF DURING STEP
5 OR 6
THE MIL COMES ON AGAIN AND THE DTC P0141 IS PRESENT AGAIN, EXCHANGE THE
DOWNSTREAM HEGO. IF DURING STEP 5 AND 6 THE MIL DOES NOT ILLUMINATE
AGAIN,
EXCHANGE THE ALTERNATOR (IF NOT ALREADY DONE AT STEP 1).