TIP: Before you replace that MAF

This is redundant or obvious to most readers on here, but we still see instances of folks writing about performance/driveability problems and saying they have already 'replaced the MAF' -usually on advice of their mechanic- and it made no difference or the problem came back.

  1. Mass Air Flow sensors are expensive and usually arent the problem after all.

  1. They are far more rugged than most think, even though the elements look delicate.

  2. Since they dont really fail all that much, if you have a fairly popular make, the salvage yards are full of perfect suitable replacements... just have to match them exactly by numbers.

  1. They DONT WEAR OUT.. but they're sometime subject to electronic chip failure.

Most PCM systems are designed to use an alternate-run paradigm if the MAF fails.

So the BEST thing to do if you have a driveability problem is to disconnect the MAF wiring connector. If the problem IS in the MAF, you'll likely see the engine runs better {remember it wont be as efficient, and the CEL will light} If it runs WORSE, the problem is somewhere else.

Instead of replacing it, CLEAN it first! Unlike the IAC, cleaning usually fixes the MAF problem.

Codes shown on MAF: Think about what the code says.. if like "Out of range" or no Signal: then the MAF or wiring to it is bad.

If it equates to "Too LOW output" try cleaning.

HOW IT WORKS: Measures air flow by tracking current needed to heat the sense element; on dual element types, one measures ambient air temp, outside the air flow.

Dirt on either is like putting heated mittens on a thermometer.

Reply to
Backyard Mechanic
Loading thread data ...

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.