# 2006 Subaru Forrester Misfire (39,000 miles)

**URL:** <https://community.cartalk.com/t/2006-subaru-forrester-misfire-39-000-miles/31270>\
**Category:** Maintenance/Repairs\
**Tags:** misfire, subaru\
**Created:** [June 1, 2009, 12:23pm UTC](https://community.cartalk.com/t/2006-subaru-forrester-misfire-39-000-miles/31270 "2009-06-01T12:23:01Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![TSAndersen](https://avatars.discourse-cdn.com/v4/letter/t/838e76/32.png) [@TSAndersen](https://community.cartalk.com/u/TSAndersen)\
**Post date:** [June 1, 2009, 12:23pm UTC](https://community.cartalk.com/t/2006-subaru-forrester-misfire-39-000-miles/31270/1 "2009-06-01T12:23:01Z")

</div>

My wife encountered a series of hesitations and shudders on return from a round trip from Pittsburgh PA to Elmira NY. The check engine light came on then off. Now, after a local trip at home, the Check Engine light is on and the Cruise light flashes continuously; the cruise control is inoperative and the cancel/ on/off, and other controls have no effect on the flashing “Cruise” indication. Moments of hestitation continue, particularly when slowing & accelerating from stop.  
  
 Trouble codes indicate misfire an Cylinders 3&4 with pending misfire codes for Cylinders 1&2. Here is the “freeze Frame” data from an Actron CP9180 scanner:  
  
 Non OBD Freeze Frame  
  
  
  
 Frame 1 Mod $10  
  
 TROUB CODE P0303  
  
 ABSLT TPS % 78.8  
  
 ENG SPEED RPM 1632  
  
 CALC LOAD % 100.0  
  
 MAF FLOW GR/SE 30.97  
  
 MAP KPA 96  
  
 COOLANT ?F 147  
  
 IAT ?F 78  
  
 IGN ADVANCE DE 6.5  
  
 ST FTRM1 % 35.1  
  
 LT FTRM1 % 3.1  
  
 ST FTRM3 % -100.6  
  
 LT FTRM3 % -100.6  
  
 VEH SPEED MPH 3  
  
 FUEL SYS 1 CLSD  
  
 FUEL SYS 2 N/A  
  
 O2S12 V 0.025  
  
 ST FTRM12 % 0.8  
  
 OBD2 STAT CA

---

<div class="post-metadata">

**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\
**Post date:** [June 1, 2009, 11:03pm UTC](https://community.cartalk.com/t/2006-subaru-forrester-misfire-39-000-miles/31270/2 "2009-06-01T23:03:08Z")

</div>

Short term fuel trims are all out of wack. It looks like, on your engine, that fuel trim is calculated for each cylinder.  
Coolant temperature is 147F degrees; which is too low for closed loop operation; yet, the freeze frame shows Fuel System 1 closed loop.  
The engine computer sees the MAF (Mass Air Flow) sensor measured the amount of air flow as 30.97 gram per second. You’ll have to go to the tables to see if this is what it should be for the load and speed. The speed is given as 3 mph, at 100% load, with the throttle at 78%. A fairly heavy acceleration was done, and the DTC and freeze frame were set in the engine computer.  
Check the engine coolant temperature sensor with an ohm and volt meter.  
The VSS (vehicle speed sensor) signal may not be getting where it’s supposed to; so, check that. Check the ohms and volts on the MAF. The values and how-tos are in the repair manual.  
This site shows the available repair manuals. Register and check it out: [http://www.autozone.com/autozone/catalog/parts/partsShelf.jsp?displayName=Manual+-+Vehicle+Maintenance&currentPage=1&categoryDisplayName=Engine+Management&navValue=15900108&itemId=prod61252&parentId=cat30067](http://www.autozone.com/autozone/catalog/parts/partsShelf.jsp?displayName=Manual+-+Vehicle+Maintenance&currentPage=1&categoryDisplayName=Engine+Management&navValue=15900108&itemId=prod61252&parentId=cat30067)