2005 Outback XT: Wheezes, Lurches, Stalls

Hi all,

I was out running errands on May 10th. I was at stop light and when I attempted to accelerate after it turned green, my car started to “stutter”. To me, it felt like being a passenger in a car with someone who doesn’t know how to drive a stick shift. I pulled into a parking lot, shut the car down, waited a few seconds and restarted. No error lights came on. I pulled back out on the road and experienced the same sensation. I soon found myself behind a school bus and noticed that if I put the gas down hard, the problem did not occur. I was muddling through like this until I came to a hill and the car felt like it was losing power and didn’t want to down shift. Eventually I made it home and rjtigger was able to replicate the problem immediately, although on later tests that evening it seemed fine.

Since then I have only had the problem occur on perhaps 3 or 4 occasions. The last one was so severe that the car stalled when I stopped at a stop sign. I was able to restart it and drive maybe 100ft to a light, where it stalled as I was attempting to stop. At that time I was able to restart it, but it immediately died. I called AAA and had it towed to the dealer.

I would describe the overall/general sensation when this problem occurs as powerless, lurching, borderline backfire, wheezy. Once the problem starts, it does not go away, although it does not happen every time I drive my car.

The facts:

* 53K miles on car

* Use 91 octane or above from name brand gas stations

* Synthetic oil (last changed @ 51.5K)

* All dealer maintenance (on schedule)

o Had two intake tumble generator valves and 02 sensor replaced about two years ago

o 45K service done a little over a year ago

* No modifications to car or after market stuff, except for tires and wipers

* No check engine or other warning light ever

* With one exception (may not be relevant) problem has only occurred during city driving

* Had driven 33 miles since last fill up when it first happened

* Have filled the tank twice since then, and driven from MA to PA and back (750 miles round-trip), as well as normal local trips

When I called the dealer today they said that they had hooked it up to the computer but there were no error codes. I’m not sure if they have done any other tests, besides the three test drives where they were unable to replicate the problem.

Any ideas as to what might be causing this, what tests could be done, or the best way to approach the dealer/mechanics/Subaru to get this fixed? What would you do?


I would suspect the throttle position sensor, MAF sensor, or possibly the O2 sensor may be causing the trouble.

Thanks for reply and apologies in advance if this is a stupid question…Why wouldn’t a sensor throw a code?