Porsche Parts Catalog Porsche Accessories Catalog Porsche Technical Articles Porsche Tech Forums
 
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
 >  >
Varioram MAF Sensor Replacement
 
Bookmark and Share

Pelican Technical Article:

Varioram MAF Sensor Replacement

Time:

1 hour1 hr

Tab:

$65 to $150

Talent:

**

Tools:

Flex-shaft, 7mm socket, 10mm wrench

Applicable Models:

Porsche 993 Carrera (1996-98)
Porsche 993 Carrera 4 (1996-98)
Porsche 993 Carrera 4S (1996-98)
Porsche 993 Carrera S (1998)
Porsche 993 Targa (1996-98)
Porsche 993 Turbo (1996-97)

Parts Required:

MAF sensor

Hot Tip:

Do not use oiled filters

Performance Gain:

Better mileage

Complementary Modification:

Replace air filter

The mass air flow sensor (MAF) is used to measure the amount and temperature of air that is entering the engine at any one time. The mass air flow sensor senses the total amount of air passing the sensor and allows the fuel injection system to adjust the fuel mixture to compensate for cold weather and/or high altitude conditions.

The first indicator that you might have a problem with the MAF is the presence of a check engine light (CEL) on your dashboard. The check engine lamp can be caused by a wide variety of problems with the engine: you need to read the codes from the computer to get a starting clue as to what the problem is. However, the engine will not be operating at peak efficiency, and you will most likely experience a loss in power and a decrease in gas mileage as a result. It's best to get the problem taken care of relatively quickly, as running the engine in this condition can potentially cause damage to other components like the catalytic converters.

Vacuum leaks and other air leaks in the system can cause MAF sensor errors. If you have leaks in your air intake downstream of the sensor, then the MAF will be sensing less air than the engine is actually receiving. You should carefully inspect all of your hoses, clamps and intake tubes for air leaks prior to replacing the sensor.

The MAF sensor is located at the front of the engine just to the right side (red arrow).
Figure 1

The MAF sensor is located at the front of the engine just to the right side (red arrow). You will need a long flex-shaft tool to reach behind the manifold when removing the MAF

Begin by releasing the two clips for the air box lid (red arrows) and remove the lid and filter, note that on standard transmission lids there will be an additional hose you need to remove.
Figure 2

Begin by releasing the two clips for the air box lid (red arrows) and remove the lid and filter, note that on standard transmission lids there will be an additional hose you need to remove.

Use a 10mm wrench and remove the bolt that holds the wiring harness and air box to the top of the intake manifold (yellow arrow).
Figure 3

Use a 10mm wrench and remove the bolt that holds the wiring harness and air box to the top of the intake manifold (yellow arrow). Reach in and squeeze the wiring connection for the air temperature senor and disconnect wiring from the sensor (red arrow)

Disconnect the wiring to the MAF sensor by turning it counter clockwise (red arrow).
Figure 4

Disconnect the wiring to the MAF sensor by turning it counter clockwise (red arrow). Next you will need to use a flex-shaft and 7mm socket to reach the hose clamp that holds the MAF to the manifold (yellow arrow)

With the clamp loosened reach in and rotate the MAF housing towards the front of the vehicle until the electrical connection is pointing straight up (red arrow).
Figure 5

With the clamp loosened reach in and rotate the MAF housing towards the front of the vehicle until the electrical connection is pointing straight up (red arrow).

Next use your flex-shaft and 7mm socket and loosen the clamp connecting the inside of the airbox housing to the lower hose (red arrow).
Figure 6

Next use your flex-shaft and 7mm socket and loosen the clamp connecting the inside of the airbox housing to the lower hose (red arrow). When separating the airbox make sure this clamp does not drop down into the engine as it is a pain to find.

Reach your hand into the MAF and push the air box off of it while slightly lifting the box (red arrow).
Figure 7

Reach your hand into the MAF and push the air box off of it while slightly lifting the box (red arrow). The MAF housing will not come out of the engine bay while attached to the airbox

Lift the airbox up and out.
Figure 8

Lift the airbox up and out. It is a tight fit but take your time and it will slip out.

With the airbox out you can see the air temperature sensor (red arrow) and the two spuds the air box sits on (yellow arrow).
Figure 9

With the airbox out you can see the air temperature sensor (red arrow) and the two spuds the air box sits on (yellow arrow).

You can now reach in and slip the MAF housing (red arrow) off the intake and out from the engine.
Figure 10

You can now reach in and slip the MAF housing (red arrow) off the intake and out from the engine.

With the airbox and MAF sensor out of the car you can see how it rotates in the airbox to clip into the box (red arrow).
Figure 11

With the airbox and MAF sensor out of the car you can see how it rotates in the airbox to clip into the box (red arrow). This is an important step when reinstalling as you will have to place the MAF housing back into the manifold in the straight up position and then when the airbox is installed rotate it towards the rear to clip it into place.

Here are the two mounting studs that the airbox will sit on (red arrows).
Figure 12

Here are the two mounting studs that the airbox will sit on (red arrows). The forward stud is missing its spacer. Installation is the reverse of removal.

Bookmark and Share

  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Project/Wish List]
  [Privacy Statement]  [Contact Us] [About Us] [Shipping] [Careers]

Copyright © Pelican Parts Inc. -    DMCA Registered Agent Contact Page

Page last updated: Mon 12/5/2016 03:07:04 AM