1.6 misfire help please

[mdibb2009]

Hi guys, after some help asap if possible

For the past 3-4 weeks ive had a problem with the car lacking power every so often.

I could drive for half an hour with no problem, then all of a sudden it would start playing up, lumpy idle in traffic, and put my foot down and it wont hardly move, get upto about 3000rpm then all of a sudden it would pick up and shoot off.

Now whatever is wrong I think has gotten a lot worse as the car now constantly sounds like a subaru, it sounds like I have a massive hole in my exhaust lol.

Ive been under the car and cant see anything wrong with the exhaust.

ive also just plugged the car into my cheapo vag com with vcds lite, here are the results :

4 Faults Found:

00525 -  Oxygen (Lambda) Sensor (G39)

00537 - Lambda (Oxygen Sensor) upper limit

00525 - Oxygen (Lambda) Sensor (G39): Signal too Low

00557 -  Pressure Switch; Power Steering (F88)

Im guessing it could be the o2 sensor then ? could this cause a misfire ?

Thanks for any help guys

Thanks very much

[mdibb2009]

I have also noticed a strong smell of petrol sometimes aswell

Thanks guys

[richw911]

Yes replace the sensor 

[mdibb2009]

Thanks for your reply mate

Could I ask, why would the o2 sensor cause a misfire ? Just for my own knowledge thats all :-)

Thanks again

[dan2252]

causing it to overfuel, run rich,  i gess? my 1.8 t has same sort of faults as you have but its got a coolant temp sensor fault in  as im gessing the sensor is saying to the ecu im cold... so it injects more fuel

[mdibb2009]

Thanks mate

 ive just done some live data from vcds and here are a few :

engine speed - 800/min

lambda voltage - 1.23v

injected quantity - 108.50 mg/str

throttle valve ange - 7%

throttle valve position duty cycle - 26%

injection period - 3.30ms

intake air mass - 2.84 g/s

voltage supply 14.22v

lambda regulation 0.0 %

 I also only seems to start misfiring when warm

Can anyon tell me if these figures look ok or not ?

Thanks very much