07.09.2020, 20:59 
	
	
	
		Went to the tuv again, now it has higher lambda and high co. I think indeed the o2 sensor is bad and got worse, the car is running in open loop that's why  it's 0.4 volt. I ordered a new sensor and will update. I think the scope was just showing noise, I am not sure this cheap scope can show low voltage properly.
	
	
	
	
	


