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IAG Performance MAF Block Off MAF Sensor Block Off Plate (Silver)

Mass Air Flow Sensor Block-Off Plate


IAG Silver MAF Sensor Block Off Plate for 2002-07 Subaru WRX / STI.

  • Seals MAF sensor opening when not required
Pricing: $41.99


Subaru: Impreza 02 - 07 WRX STI / WRX

  • Attention: Special note about using ARP Case Bolts - IAG recommends line honing the case when using ARP Case Bolts to remove any distortion created by the hardware. IAG installs ARP CASE BOLTS with 30W engine oil using OEM SUBARU torque specs and procedures. Other torque specs and lubricants may lead to case distortion damage.
  • Bore and hone additional and required before final assembly!
  • Case Includes: (x1) IAG Stage 3 Closed Deck Converted Case Halves (Using brand new EJ25 Case), Machined for OEM 11mm Head Studs Head Gasket
  • During this stage, the flanges left from machining the inserts are milled close to the case deck surface. Features such as coolant passages and case bolt access positions are machined. Finally, each deck surface is machined true and flat using a Poly Crystal Diamond insert.
  • IAG Recommends JE Pro Seal .039 inch head gaskets: JE PN# SB1001-039 are for use with S20, B25 & D25 Cylinder Head Castings (04-06 STI, 06-14 WRX, 04-13 FXT, 05-12 LGT, 02-05 WRX) JE PN# SB1003-039 are for use with V25, W25 & N25 Cylinder Head Casting (2007-20 STI)
  • If using on 2002-05 Subaru EJ20 2.0L WRX additional modifications and parts are required.
  • Once the pockets are machined, the case is removed from the mill and placed into a block oven at a low temperature. Our pre-machined closed-deck inserts are simultaneously chilled using dry ice. When the case and inserts have reached our desired temperature, they are moved into our install station, which holds the block and lightly presses the inserts into position on one side of the deck surface. This process is repeated on the other side and then the partially completed case is moved to a cooling rack. In the next step of our process, the case is loaded and fixtured back into the VF-4SS after reaching room temperature.
  • Please Overbore must be performed (99.75mm is the preferred bore) before assembly!
  • The IAG Closed Deck starts with a new OEM EJ25 bare case. The case is loaded and fixtured to a 4th axis rotary indexer in our 2015 Haas VF4-SS CNC Vertical Machining Center. It is supported by the main journals using a precision ground 2-inch bar and tailstock which ensures the datum is the main journals. This method gives us a true reference point to perform all machining operations. A Rennishaw probe is utilized to check that the case is fixtured true and once confirmed the machining process begins. Once the case is fixtured, the first step is to mill out 12 pockets for CNC inserts. Rather than attempting to install inserts into an inconsistent cast case, the pockets are milled out to exact dimensions creating a consistent area that accepts our precision inserts.

The IAG Performance MAF Sensor Block Off Plate for the 2002-07 Subaru WRX / STI is designed to seal the MAF sensor location on cars that are converted to speed density tuning (where the MAF sensor is no longer needed). The block off plate can be used in a wide range of aftermarket intake applications utilizing a stock-style MAF flange. The IAG block off plate is engineered and manufactured in our own facility in Westminster, Maryland. The product is machined from 6061 billet aluminum, and each plate features our laser engraved logo on the top. The IAG MAF Sensor block off plate includes a new o-ring for easy installation.


  • IAG-AFD-4000SL
  • IAG-AFD-4000SL
  • 887753777096
  • IAG Performance
  • New


Shipping Information

  • Item Requires Shipping
  • 0.1 lbs.
  • W0.1500” x H1.0000” x L3.0000”

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