GM LS3/L99 and LS7 MAF Sensor

Designed to provide a smooth idle and consistent power throughout the entire powerband. GM offered MAF sensors that were manufactured by 2 difference manufactures; there is a “weak” and a “strong” sensor. The “weak” sensors do not show the same resistance levels as the “strong” sensors. The MAF sensors that have been identified as “weak” read 1560-1670HZ at idle while a “strong” MAF reads at 1800MHZ. When driving on the road at partial throttle the MHZ are slow and weak in response to throttle changes which is what causes the hesitation. When at wide open throttle the “weak” MAF shows 120-170MHZ lower than the 8600MHZ “strong” MAF sensors show on the same car. The fuel trims with a “weak” MAF can range from -25% on the high end to -3% with a simple aftermarket panel replacement filter. Simply remove the “weak” sensor and install a “strong” sensor and within seconds the fuel trims go to 0% and MHZ are back to 1800+. This will completely change the responsiveness of the car.

How to determine if you have the “weak” MAF Sensor

When the MAF sensor is removed you will see an indented portion on the back side. Within this indented section there will be a letter or a letter followed by a number like the MAF shown above. If you have a MAF with a single letter you have a “weak” MAF sensor and if you’re MAF has a letter followed by a number you have a strong sensor. If you already have the “strong” sensor you have nothing to worry about.

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