nick46

Hi guys, this is my first post on here and there is a bit of history, so I'll start from the beginning!
I have a 2007 5Dr PFL with 43300 miles on it. I have owned it for about 2 1/2 years now and love it.
A few months ago I had a downpipe and secondhand 200cell cat fitted to the cat back system I already had. I then started running Bluefin stage 2.
Soon after, the engine light came on, so I plugged the bluefin in to get the code - P0133. I looked it up to find out what it meant - 'HEATED O2 SENSOR CIRCUIT SLOW RESPONSE BANK 1 SENSOR 1'. Contacted Ford who said it was the lambda sensor in the downpipe. So I bought a brand new Bosch replacement and fitted. The fault cleared and all was well.
Now, a couple of months and 3000 miles later the light has come back on with the same fault! Surely the sensor can't have failed already? Although I have emailed the supplier as it came with a 12 month warranty. Just waiting for a response.
Anyway, what else could cause this fault to reoccur?
Just for your information, the car has been serviced by Ford from new, it is used daily and is a family car. I don't drive it like I stole it ( I'm 35 married with kids so my boy racer days are long gone!). I drive it just like any normal family car, with the occasional bit of fun.
Right I think I've given just about all the information that is likely to be needed!
What's going on? Cos I ain't buying new lambda sensors every few months!
Any help and advice would be greatly appreciated.
Nick.

GVK.

Is there an exhaust leak pre-cat?

nick46

Hi and thanks for your swift response.
To my knowledge there are no leaks, but I guess that's something I can check. Tarnock Ford fitted the downpipe so I wouldn't expect it to leak bit I guess there can always be a first time.

nick46

I have checked the exhaust and the only thing I could find was maybe the slightest of leaks at the joint between the cat and the cat back system. I couldn't even feel it blowing. I even held a piece of tissue by the suspect area and it wasn't blowing that or even changing the colour of it. The only signs of a leak was a black mark on part of the joint. Therefore, Along with the fact that it is post cat, I don't think this would cause the fault. Remember, the fault I have is with the pre cat sensor in the downpipe.
I also checked the sensor cabling and plug for any signs of damage, and it all looked like new.

nick46

I have also heard from the company who supplied the sensor (Carparts4less), regarding the warranty. They want me to fill out a warranty form with all the details of the fault and send it back to them along with a copy of the original invoice and also the component itself. The claim will take 4-6 weeks as they need to send the component back to the manufacturer (Bosch) for testing.
Now, I have two problems with this:
Firstly I must have thrown the invoice out with the box. (Really annoyed with myself about this as I keep bills and invoices for everything!).
Secondly and more importantly I can't be without my car for 4-6 weeks while they sort it out! I was hoping they would send me a new one and then I could send them the old one.
Will give them a ring tomorrow and explain the situation, but if anyone has any suggestions as to what I can do, then I'd love to hear them, as I feel a bit stuck now.
Also keep coming with the suggestions as to why the fault may have reoccured in the first place.

Cheers guys,
Nick

nick46

Come on guys, considering this is supposed to be one of the biggest Ford forums in Europe, surely someone must have come across this fault before. I mean, at the end of the day it's just a Focus and they aint exactly rare or exotic cars!

RichieST

iTrader: (2)

Do we need to do the leg work for you?

http://lmgtfy.com/?q=p0311+dtc



http://www.obd-codes.com/p0133


P0133 OBD-II Trouble Code

Technical Description

Oxygen Sensor Circuit Slow Response (Bank1, Sensor1)

What does that mean?

This is considered a generic powertrain DTC (code). That means it's definition is the same for all makes and models of OBD-II vehicles, however specific repair steps may vary depending on the vehicle. This trouble code involves the front oxygen sensor on Bank 1.




This code indicates the engine air fuel ratio is not being adjusted by the oxygen sensor signal or the ECM as expected to do so, or not adjusted as often as expected to do so once the engine is warmed or under normal engine use.

Symptoms

You will likely not notice any drivability problems, although there may be symptoms.

Causes

A code P0133 may mean that one or more of the following has happened:
•The oxygen sensor is faulty
•The wiring to the sensor is broken / frayed
•There is an exhaust leak

Possible Solutions

The simplest thing to do is to reset the code and see if it comes back.

If the code comes back, the problem is more than likely the front Bank 1 oxygen sensor. You will likely wind up replacing it but you should also consider these possible solutions:
•Check and fix any exhaust leaks
•Check for wiring problems (shorted, frayed wires)
•Check the frequency and amplitude of the oxygen sensor (advanced)
•Check for a deteriorating / contaminated oxygen sensor, replace if necessary
•Check for inlet air leaks
•Check the MAF sensor for proper operation

andi-p

To me it would make sense to have the component tested on the vehicle. Any faults would potentially show up in the test data. I had similar fault on customers Zafira VXR. He had a Lambda probe replaced. Fault code came back after 1000 miles. I carried out component test and the data came back to being faulty sensor. Replaced sensor quick check of the signal data and all is well.

GVK.

As per the info RichieST posted, is there another fault with the fuelling that is causing the issue?

Would expect a rich/lean code also though.

nick46

Excellent, thanks guys for the fast response. From what has been said and the checks I have done I have narrowed it down to:
-Inlet air leak
-Maf sensor
-Faulty O2 sensor
How do you check the amplitude and frequency of the O2 sensor? and what should these values be?
Also how do you check the MAF sensor?

Since I have reset the code I have driven 100 or so miles and it hasn't come back, but I'm not holding my breath. Is it possible that it could just have been a glitch, do these faults occasionally just come up for no apparent reason?

GVK.

In some cases its possible for a glitch that trips the EML on, sometimes OEMs bring out software updates to combat these. As you're on Bluefin, is there updates available for your car?

The 02 sensor once in 'closed loop' operation where the ECU is controlling the AFR will go anywhere from 0.2 lean to 0.8 volts rich it alternates between the 2 going from rich-lean with an average of 0.45 for Lambda 1 (14.7:1 AFR)

These voltages can be viewed on live-data on things like the Ford IDS dealer tool which shows them in graphical form.

Or,Ideally an ocilloscope is required.

More reading - http://www.picoauto.com/applications/lambda-sensor.html

Maf sensor operates up to a max of 5 volts but ECUs live data can sometimes show a reading in g/s (grammes/second) of airflow and this can be monitored for a smooth increase up to its peak airflow which can be calculated to a rough BHP reading. (a 150hp engine should show 120 g/s peak)
Not all ECUs support this data though.

nick46

Right, time for another update!
I decided to do an experiment and remove the Bluefin map and restore the original. After two tanks of fuel and 600 miles the fault has not returned, which to me points to a fault with the Bluefin map. So I have now emailed Superchips to see what they say about it. Will report back when I get their response.

GVK.

Interesting.

Post up any updates.

nick46

Well I've heard back from Superchips and it's no surprise that they are saying it must be the car at fault! They did however say that it was a very odd set of circumstances.
I really don't know, it's confused the hell out of me. I guess the only way I'm gonna get to the bottom of it is to let the professionals have a look, but as the car is performing perfectly I'm reluctant to do this as I don't trust any of them!
I wish I'd never bothered with this modifying malarkey as it's nothing but trouble. I guess it goes back to the old saying "if it ain't broke don't fix it".
If I do ever find out what's going on I'll post it on here.