Missfiring engine

[MarT2]

Hi all!

I have a S2 ABY converted to ADU.

After some 0-100's km/h, the car started missfiring at around 5000rpm.
At low revs, the car is fine, and have full boost (1'4-1'6bar), but since 5000 rpm is misfiring.

I changed one coil 2 months ago, so I suspect that another coil was failing, and changed the other 4 coils.

After waste a lot of money (about 600€) changing the coils, the car still misfiring.

I checked the fault codes:

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00525 2342 Lambda Sensor, G39

- Signal to B+
- Signal to ground
- No change in signal

---------------------------------------------------------------------

00537 2341 Lambda sensor control

- Maximum control limit exceeded
- Minimum control limit exceeded
---------------------------------------------------------------------

The lambda sensor, injectors, fpr,, plugs, coils, boots, fuel filter, air filter, maf, 044 fuel pump, are new (1000km).

What could be the problem?

A faulty POS? How can I check it, if isn't misfiring at idle?

Thanks a lot.

[MarT2]

I removed the fault codes, and readed again.
00525, 00527, and 00515 (new):

--------------------------------------------------------------------------

00515 2113 Camshaft Position Sensor, G40

- Open or Short circuit to B+
- Signal to B+
- Short to ground
- Signal to ground
- Mechanical fault

--------------------------------------------------------------------------

[JP]

Has your car been remapped? Sounds like a generic chip I once fitted where they turned the boost up and let ecu do most of fueling correction through maf and lambda resulting in missfiring and hesitation as it ran lean at the top end.

[MarT2]

Is a stock ADU ecu. The car was fine until a couple of days, standard rs2 boost (1.4-1.6bar).

It's possible that the timing belt disengaged 1 tooth?

[MarT2]

Today I revised the timing belt, and it mooved 1 tooth to the right!
I see too, that the new RS2 water pump it's losing coolant through the shaft.

The big pulley (aircon, steering and alternator) oscillates a lot when the engine is running. I didn't see any cracks in the rubber, but oscillates a lot. It's normal or it's time to change it?