difference between air flow meters

[disco-v8]

ok im thinking of changing my airflow meter on my 3.9 hotwire V8 disco but seen that there is a 3AM and a 5AM version!!!!!!

whats the difference????


oh and also im intrested in changing it to a later 4.0/4.6 airflow meter as ive heard that it has less airflow resistance giving it better airflow to the engine...... ive already gathered that its got one less pin in the plug, which im asuming is the power to the hot wire part.....

will this airflow meter cause any problems????

[Range Rover Blues]

I can't find it now but I read an article about fitting the P38 MAF sensor as the hole in the middle is bigger so it lets more air in, that can free up more power when running flat out.

As for the difference I don't know, they both do the same job, but then the ECUs were tweaked almost monthly at one point :roll: