As deanyel recommended you need to pull codes from the EA, LH modules for sure. You can build the home-brew readed described in MENU#2. It's worth the effort.

Bosch specs O2 sensors for 60Kmiles so you could be due. Also don't forget the MAF sensor. . it might be contaminated, Menu#4a.

The rubber 'tips' of vacuum lines usually develop cracks which are not visible until you actually bend them a bit.

If Lambda is not functioning, I'd fix that first and that will probably fix the knock sensors.

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Regards . . . . JimF
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'94 S500 Cpe

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