So the car stranded my wife at the store. I go in the Jeep and jump it. We drive in formation to Autozone.

 

I buy a new battery and replace it in the lot. Car cranks but wont fire unless it is floored. And then the RPM are less than 1500 with it floored. It sounds like it is missing badly. No codes appeared on the scan tool.

 

I towed it home (about1/2 mile). It sits in my drive.

 

What am i missing? all I did was replace the battery.

 

130,000 miles on the car. Runs strong till today.

 

Ideas gents?

Update:

 

I have fuel pressure and spark at all 4 leads. The air filter is clean. The car will fire but not run unless floored and then it's rough as hell.

 

I'm letting it sit with the neg terminal off for a while to see if it needs to think about what it did and why good cars don't act this way:) .

 

I'm stumped after that.

 

Anyone want a gently used Outback?

Update:

 

After setting for 30min with the neg term off it fired right up.

All units stand down. False alarm. But at least I got to tow something with my Jeep finally.

It seems that disconnecting power to the ECU for too short a time can "confuse" it. Although it doesn't address the same model year as yours, see http://endwrench.com/images/pdfs/RoughIdle.pdf -- the problem appears to afflict more than just those mentioned in the article. I suspect that the "learned" parameter values get corrupted, and a longer disconnect time allows the ECU to truly reset to default values.

I think you're right on the mark OB99W. This has happened to me a few times on a few different cars. Kinda like powering down a pc in the middle of it starting up. If I disconnect a battery I usually leave for a while.