Think it needed cleaning? Got to thinking about how encrusted my air filter was when I just replaced it (like it was covered in road tar sealant).




Cleaned it with CRC MAF cleaner =

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Haven't driven it yet. Still waiting on UPS lost part to replace fuel pump.

 

Dell: That dark bulb is the IAT - Intake Air Temperature sensor. Definitely clean it, but more importantly, clean the MAF - Mass Air Flow sensor wires 'concealed' up inside the black plastic MAF tube.

IIRC, a dirty MAF sensor will under-report the quantity of air, so the EMC will inject less fuel than the engine really requires, causing a lean condition, particularly a rough idle when cold.

I can't count how many friend's engines instantly ran smoother after we spent ~10 minutes spraying ~50 cents of MAF cleaner on the factory original sensor with 100+K miles accumulated road grime.

Source: htthttps://howtune.com/articles/162-cleaning-the-maf-sensor-on-a-mazda3#chunk-4926

 

Wow, lucky I just sprayed the daylights out of everything including down that "tube". See, OCD does have advantages sometimes......

 

The sensor should be cleaned with every air filter change. Also if you use the high flow air filters with the oil that oil ends up on the sensor.