E39 540i Oxygen Sensor - Misfiring

[///MALCOLM325]

Hi Guys,

So today my car started missing slightly, took it to the mech before he closes and the codes showed the oxygen sensor pre cat bank 1 is faulty causing cylinder 7 to misfire. Checked around most places cant get one anywhere. As I got home the car is missing badly, feels like a rocking boat.

Does someone perhaps have one? or knows where I can get one on Saturday? I need it to be sorted before Monday for work.

One more thing : Any views on a de-cat?

 

[Nic_s]

you can maybe pm LZ as he might be able to point in the right direction. I think he had the sensors on his M5 done.

 

[clutchplate]

kinda sounds like an air leak to me .. not a dead lamba sensor ..
easiest way to check is just unplug all your lambda sensors and drive the car around the block ..

if the misfire goes away then its probably your sensor ... if it doesn't I'm almost certain you have a air leak somewhere on your intake ..

first thing to check is check the hoses that go into the PCV valve at the back of the intake manifold .. they come off sometimes or crack .. then check all the littles hoses on top of the manifold .. and the brake vacuum hose that goes onto the back of the firewall behind the intake manifold .. check all the hoses ..

 

[///MALCOLM325]

Thanks, it turned out to be cylinder 7 coil pack. I got a replacement from goldwagen for R395 changed the plugs while I was at it.