Having trouble with my wife’s 2000 Legacy Outback wagon………2.5L, AT, 72,000 miles.

 

 

• Intermittent off-idle hesitation….unverified by dealer
  
• Intermittent hard starting (well, not really “hard” just cranks two or three times longer than normal)……….unverified by dealer
  
• MIL on with a P0420 code resulting in dealer replacing converter under warranty
  
• MIL on again (did not get the code) resulting in dealer replacing the rear o2 sensor
  
• Had real bad hesitation and stalling while pulling a small trailer recently. No MIL or stored codes and problem went away when car was driven later without the trailer………..strange.
  
• Now, MIL currently on, intermittently, with a P0170 code
  

 

I have also replaced the plugs with NGK OEM spec. I have replaced the fuel filter, air filter, and have visually gone over the airbox connections, hoses, and electrical connections. In addition, I loosened and retightened the various ground connections I could find under the hood. Oh, I also replaced the battery just as a preventive measure.

 

 

 

Questions:

 

 

 

Since the front o2 sensor is a possible cause for the hesitation and maybe the P0170, should I just take the gamble and put a new one in?

 

 

 

Others have suggested cleaning or replacing the MAF sensor. Where is this thing located on an Outback?

 

 

 

I also suspect a fuel pressure problem. Is there a crude way to check that? Could I possibly have a bad replacement fuel filter (bought it a NAPA)?

 

 

 

Has anyone had similar problems? What was the cause(s).

 

 

Thanks in advance,

Tim

i dont think its fuel pressure. Maybe a weak TPS sensor, since there seems to be a pattern to the hesitaion ..

 

 

nipper

i dont think its fuel pressure. Maybe a weak TPS sensor, since there seems to be a pattern to the hesitaion ..

 

nipper

 

Good thought. Is there an easy way to test the TPS?

Replace the Front A/F sensor (02 sensor) it will fix your problem

It is a very common problem with the symptons you are describing

 

SEA#3

$100.00 for a new front sensor, 10 minutes to install. Cleared the code and it has not come back. My wife says she noticed the slight hesitation is gone...............a pretty good sign that it's fixed!

 

Got my fingers crossed that the MIL/CEL stays off.

 

Thanks,

Tim