Sensor plate
 

Hello guys,

I have removed the intake air filter housing to clean up some dirt and found the air flow sensor plate with the throttle body dirty. I removed all of the air flow mass and wanted to replace it with a very clean one which is set a side as a spare. I noticed the sensor plate on the spare one has a bigger diameter "10.5cm" than the existing one "10.0cm" the one I just removed from the car. Now the air flow mass has a bigger opening than the previous one. Does this Contribute to give more air flow to the engine in turn give more power?
What model does the smaller sensor plate go for? Is it for 420sel?
Any help would be highly appreciated and thanks.

There is supposed to be dirt in there after 20+ years. Just give it a good cleaning and put the old one back on. The other one is mostly likely for a different engine and will make yours run like crap.