so a bit more on the issue. i can get it to throw a misfire if i hold the revs at 3k rpm for 20-30 seconds. itll then throw a code and go into reduced engine mode. it throws P0301

roverguy7 wrote:

Haylands, that really isn't true for these engine management systems (page 11 has a better description than I'll make) but was correct for earlier systems.

I haven't read through that document in years now, but I remember something in it being worded very deceptively, so don't follow it's process to the t. This relates only to the Denso EMS setup of the 4.4/4.2, but does also apply to the Denso 5.0 up to 2013/14.

**Edit: can only images be uploaded here?
Screenshot of document attached.

so bit more of an update. I kept getting misfire cylinder 1 when idling at 3k. I assume when sat in the driver's seat(UK) that its the left side of the engine?

Anyways I tried swapping the ignition coils and plugs no dice. It still threw misfire and lean codes at 3k rpm. So this car has lpg, but i haven't used it in a while cause i broke some stuff with the gas pressure a week or two ago.

So I fixed that stuff. now when idling at 3k rpm, no misfires, still throws lean codes but no misfires so I can only assume that injector is clogged up. I assume the lean codes are from the fact its trying to emulate the petrol system.

How are you getting on? Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

waiting for cans of bg44k to turn up and a air sensor wrench so I can take mine off to take a look at them

Air sensor? Just use long nose pliers if you don’t have the right bit. What about the o2s? Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

i meant o2s sorry. but meh tool will be turned up in a day or do. itll just be me under the car with a jack so id rather make the job as easy as can be haha. learned that the hard way with the ace pipes

What is this tool you speak of? I just drove it around for about 20 minutes to get the cats hot out it in full beige mode chucked under some axle stands and got under with a spanner and hammer and they cracked loose. Then went in for a cup of tea and waited for the cats to cool down and undid the rest by hand and swapped Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

ah i was just gonna go with one of these

https://www.ebay.co.uk/itm/22mm-3-8-DRIVE-...SwHPlWeT3D

Agree with you waiting for the 02 spanner, they can be a real to get out.

When you say miss fires how many are you logging?

I have similar issues to what you are seeing.........I dont have LPG system though
I changed the post Cat on the right side and it reduced the engine light issue to virtually zero.
Changed the spark plugs yesterday and they were well worn Im assuming they were original plugs 170,000kms NGK Iridiums not a good feeling undoing them at all.

when i hold the revs at 3k rpm about 300 misfires if am understand the number correctly but only on cylinder 1.

I didnt see anything like that number of missfires, but they were on #1 cylinder (3 missfires, so im discounting them)
Have you had any knock sensor DTCs?

If you havnt taken a look at the plugs I would suggest its a good place to discount #1 is pretty easy to get at, pull iy and stick a new one in there and see what happens, if your budget allows it get a new coil pack while you are at it.

Watch out for counterfit spark plugs too

So you had occasionally misfired only on one cylinder and you changed the downstream sensor and it went? Was it obvious the misfire and what number out of curiosity? Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

On #1 cylinder
Not having any issues now after 700kms

Ok fair enough - so is the ops problem sorted now?  Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF