DURAMAX 2500/3500HD AIR FILTER SERVICE TIPS
As innocuous as an air filter seems, it plays a critical role in LMM Duramax performance.
Halsten says to stick with GM’s filter because the Mass Air Flow (MAF) sensor, which is a key to fuel delivery parameters, is extremely sensitive to changes in airflow – higher or lower.
GM designed the honeycomb-like filter specifically for this application.
Some aftermarket air filters (and cold-air intake systems) flow more air, but it’s one of those instances where more air flow isn’t always better.
“It takes an extremely small change in air mass to make big changes in the Duramax’s fuel delivery,” says Halsten as he shows me the sensor.
“I’ve seen some aftermarket filters and cold-air intakes trip P0101 codes because they create vortices in the intake tube,” says Halsten. “Those variances cause the MAF sensor to signal the ECM (Engine Control Module) there’s an airflow problem, putting the Duramax into the ‘limp home’ mode.”
It may look like a gimmick. But Halsten advises fleet mechanics to let the “filter minder” attached to the side of the air intake tube be their filter-change guide.
“If your goal is to maximize engine performance, replace the filter if you see any red showing on the gauge,” says Halsten.
“If you just want to optimize filter life, wait until the red indicator gets into that 80-percent area.”