Golf 4. 2.0L,APK engine. Rough idle, poor fuel cons. DTC P1582, P0300, P0301, P0304

[lobe]

Gday,

2003 - with APK engine - 185000kms

Scanned with a mates Launch X431 scan tool (who's a mechanic)

P0300 Random multiple misfire detected
P0301 Cylinder 1 misfire detected
P304 Cylinder 4 misfire detected
P1582 Idle speed regulation adaptation limit reached.

Plugs are fouled - black soot. At fist i suspected the MAF - cleaned with TB cleaner but no improvement.

Read up on misfire codes.

Today ive replaced (in seperate steps so i could work out what was the problem if the cars problems were fixed)

- NGK - blue plug leads (previous were cars originals
- Coil
- New Plugs - ngk bkur 6ET-10

Still no improvement ? Any ideas help ???

I suspected O2 sensor or MAF etc ( car had temp sensor & 02 sensor 75000kms ago in service history by previous owner) but showed no such codes when we scanned for faults, only the codes listed above

I cleaned the TB with cleaner for the P1582 idle adaptation max reached. I have read up on the reset using VAG.com and also that it should set itself after a number of ignition cycles etc. You can hear it when ignition is turned but car is not started. I've waited until its stops buzzing but this doesnt improve the cars idle or problem either.

When idle is poor, you can smell the car, like the mixture is out - rich. GF said is has misfired, the odd time whilst driving.
A hard rev of the accelerator peddle give black (not blue) soot out of the exhaust.

Fuel is always - BP premium, Shell V power etc, not the cheaper stuff.

I'll visit my mates tomorrow who will scan car again.

Note - background : Car did have a similar problem, about 8mths ago, i cleaned the MAF and disconnected the battery, cleared out any residual current with some improvment.
When i changed t/belt and W/P about 8 mths ago, i noticed timing was slightly out - i though this might have caused the poor idle at the time.
Have read oil consumption sticky - car uses abit but is no way excessive.

[vdubmotorworx]

main issues on that engine are number 1 before catalyst 02 sensor and air flow meter....air flow meter does not always log a fault as it just holds onto specs enough not to log a code but enough to make it run rich....VDUB...

[jDub]

I had similar problem as you, ended up changing the coil pack and it solved my problem.

[pinchies]

That error list sounds exactly like I have too, so I hope that I made the right diagnosis! I really hope mine isnt the coil pack...

What's a reasonable price for a pre-cat o2 sensor, and where should I get it from? Should I stick with bosch?

I've got a genuine bosch part I ordered from lithuania that I paid $105 shipped for, but it hasnt arrived yet, I havent had any communication from the seller so i'm not optimisitc - I've already started a paypal dispute, and i'm now looking around again.

I dont have axle stands or an O2 socket, so i'm going to have to get the mechanic to install it for me anyway.

Edit:
Replaced O2 and is running smooth now, no more rough idle. Still going to replace plugs now (must be black by now), replace T/B and clean MAF, then see where things are at.