Questions and Answers

Chevy S-10 MAF Sensor Screen Q. I've got a 2001 Chevy S-10 Crew Cab 4x4 with the 4.3 liter V-6 and I've got a question regarding the function and modification to a factory MAF sensor. Inside the MAF sensor, there is a screen. In some of the S-10 Chat rooms, they suggest removing this screen for additional air flow.

By removing this screen is there any issues with "hurting" the motor? I am to understand that Grannelli performance MAF sensors "program" the PCM for the additional air flow to increase performance.

Their web site states that although removing the screen will increase immediate performance, the PCM will "learn out" the modification and the engine will loose the performance increase. What is your view on this topic?

Thank you...

A. The PCM has one job to do, and that is to monitor engine functions and keep them as close to the ideal parameters stored in its memory as possible. So if you change something, the computer is going to do it's best to put it back where it belongs.

The MAF sensor is not the only input the PCM uses to calculate fuel mixture. It also uses the TPS, MAP and VSS sensors to see what's going on and adjust accordingly. By removing the screen you may or may not get a small increase in performance.

As for the screen, it is there for protection. The MAF is a "Hot Wire" type MAF. In other words there is a thin wire in the intake airstream that is heated to a certain temperature. At this temperature the wire has a certain resistance. Now, as air incoming air cools off the wire, the change in resistance is measured and the PCM adjusts fuel mixture accordingly. When the engine is turned off, the hot wire is heated to red hot so any contaminants that have accumulated on the wire burn off.

The screen is there to protect the Hot Wire from anything big enough coming into the engine that would damage it.