had my car back of zedword and alls been brill for days

went out yesterday for a bit of a drive and it started to miss fire on

cylinder 2

anyways investigating tonight and with the car cold it seemed ok

and when it gets warm it started again 1500>2200 rpm but would go when pushed. does it on idle/costing no load speed

 

checked all my cables and joins and plugs and all is good ...

then i disconeced the O2 sensor on that side .. and bang no missfire

and drives nice and smooth

 

would a faulty/bad O2 sensor make a missfire

 

PS i did read a few posts about the O2 sensor and testing it at 2000rpm as this is where it works

 

thanks again

Mark

mine suffered with hesitation at pull away with weak 02 sensors . when they were disconnected the problem went away .

all so forgot to say ..

 

tuck 2 of the spark plugs out and they was kinda white'ish so i think the sensor is making it run lean ?

Firstly an o2 sensor wont cause a misfire and if it fails the de fault will be for the ecu to run the engine rich for safety.lean running causes detonation.

but doesnt the O2 sensor on the turbo elbow tell the ecu how less/much fuel to use

so inefect make the engine run right

 

thanks for your help on this

 

Mark

The 02 sensor is an aid for emission control,it reads oxygen levels in the exhaust and the ecu uses this to "fine tune" fuelling for the correct Stoichiometric ratio.Even with a failed sensor it wont flood the engine to the extent it misfires.

was this ever resolved? i have same knid of problem. I have a slight hesitation on light throttle but is ok otherwise. I did have code 53 on ecu but it has cleared and now have code 55 but still have the same fault.

yes it was ... the O2 sensor went bad and was confusing the ECU and making it Missfire ... unpluged it was fine .. put a new one in and working fine still

 

Regardless of the Post above if the O2 Sensor goes wrong and is ( open circit ) 90% of the time it does this wouldnt effect the ecu .. but other short out and give the wrong signel to the ecu .. miss fire was only there when engine got warm never from starting for about 5 mins

 

Mark

Awsome ill replace my right one next week. Is there a way to replace it without taking off the elbows?

dont replace it untill u checked it .. Just unplug it from the loom and then test drive ..

remember u have one on each side of the engine

 

Mark

Yeah will do i have a new one as the ecu was telling me it needed one. I did look at changing it at the weekend but was a bit of a loss how to do it without removing the elbow!

i did mine by taking the elbow off ...

Just unplug em' period!:chinese:

Yeah will do i have a new one as the ecu was telling me it needed one. I did look at changing it at the weekend but was a bit of a loss how to do it without removing the elbow!

 

I broke mine off with a pry bar and hammer, you can then get a socket on it to undo :)

When i changed my engine i didnt bother with any O2 sensors and runs fine, no issues at all.