What do these mean? P0100, P0170 ...

[nelstomlinson]

Hello, my '96 Legacy has started running rough, dies at idle, loses power.  It smooths out a little at higher RPMs, above 2000 or so.

 

The error codes I am reading are: P0100, P0303, P0304, P0106, P0170, P0106 again.  I'm thinking that these all point to a MAF sensor problem.  Smoothing out at higher RPM suggests that I'm getting decent fuel pressure, and the MAF and fuel trim codes (100 and 170) together might explain the cylinder 3 and 4 miss codes (303 and 304).  Am I going wrong here?  Is it reasonable to replace the MAF as a starting point, or what would you recommend?

 

I have a code reader but no scan tool. 

[Fairtax4me]

Usually if you get a code for the MAF that indicates an electrical problem with the MAF or the wiring. The MAFs on the 95-96 years are known to fail. They can sometimes be fixed, but I think yours my have totally bit the dust. 

 

Make sure the wire connector is clean inside and plugged in all the way first, and make sure there clamps on the air tube are tight, and all of the 3/4" PCV and breather hoses are properly attached at both ends. The P0106 code suggests a vacuum leak, usually the smaller 5/16" hoses that run from the #3 intake runner to the MAP sensor and switching solenoid on the right strut tower. 

 

Misfiring is usually due to old/work spark plugs and old plug wires, but I would try to fix the MAF code first. A used MAF is usually pretty inexpensive. 

[nelstomlinson]

 I have unplugged and re-plugged the MAF connector.  Everything looks bright and shiny inside the connectors.  I hadn't known that the P0106 might indicate a vacuum problem, so I'll check over those hoses.  The MAF is expensive, but at least it's easy to get at.  It's below zero here, so easy to get at is a big deal.

 

Thanks!

[wtdash]

Hi,

All '92-'98 ('99 EJ25D, too) NON-turbo 2.2 and 2.5 Subarus used the same green-label plastic MAF. Maybe on the 1.8 too.

 

Part number: JECS 22680AA160 and AutECS 22680AA160F are the same. Jecs is made in Japan, I believe.

 

And although they do fail, they're cheap used. 

 

And buy some MAF Cleaner (don't use brake cleaner -too abrasive/corrosive/bad for the sensor) to clean it b4 install.

 

Another post HERE.

[mikaleda]

Ya, buy a used one from the junkyard and clean it up with MAF cleaner only.

[nelstomlinson]

Thanks, all.  I wish we had a junk yard nearby, but if we do I haven't found it.  The local parts store will get a new one down here tomorrow from the big city, and I'll let you all know how it works out.  I'll hose it down with the MAF cleaner first; that's a good tip.

[mikec03]

Use car-part.com to find nearby junk yards or order one if there are none nearby.

 

http://www.car-part.com/

[nelstomlinson]

So, replacing the MAF sensor and clearing the error codes solved all the problems. The P0106 has returned, intermittently, but the car runs fine, and the mileage has improved a bit.

 

Thanks for all the help!

[1 Lucky Texan]

that is a MAP sensor code - solenoid/sensor on/near the right (US pass.) side strut tower, should have one vacuum line.

 

hmmm...if the vacuum line seems good, maybe connecting the green connectors under the dash would cycle the solenoid so you could feel it clicking?

 

also, i ran across some mention of a TSB but. not sure if 96 year model involved; TSB # 114795

Edited March 29, 2016 by 1 Lucky Texan