'97 Outback misfire/hesitation?

[Sheldon]

This problem is hard to describe, but when just cruising down the road at
speed the car will sometimes hesitate for an instant and then pick up again.
Since the CEL never comes on I find it hard to believe it's a misfire, and
wonder whether it might be the tranny searching for a lower gear for an
instant. The car is an automatic. Once it did hesitate for an instant when
starting out from a light.

My neighbor has the same car, and when I told her the story she said hers
does the same thing. Meanwhile both cars continue to run with no other
symptoms or warning lights coming on. I don't know about her, but I tend to
cruise at about 75mph to 80.

Any ideas as to what's going on here?

Thanks

Sheldon

 

[thomashanno]

You might check out this topic:


http://groups.google.com/group/alt....323ed78d82d/6b7eef0e44f7c8ad#6b7eef0e44f7c8ad


I've driven ~360 miles since putting that stuff in, I guess I notice it
a little less, but so far it's hard to tell if that's luck or the
cleaner.

 

[Jim Stewart]

This problem is hard to describe, but when just cruising down the road at
speed the car will sometimes hesitate for an instant and then pick up again.
Since the CEL never comes on I find it hard to believe it's a misfire, and
wonder whether it might be the tranny searching for a lower gear for an
instant. The car is an automatic. Once it did hesitate for an instant when
starting out from a light.

My neighbor has the same car, and when I told her the story she said hers
does the same thing. Meanwhile both cars continue to run with no other
symptoms or warning lights coming on. I don't know about her, but I tend to
cruise at about 75mph to 80.

Change the fuel filter and dump in a container
of the expensive Techroline. If it still
does it, check for a trouble code.

 

[phatirejunky]

Sounds exactly like poblem I had with my '02 Forester at about 70,000
miles. I replaced plugs, wires, fuel filter, still had hesitation.
Took it to independant shop, they supposedly pulled injectors and
cleaned, didn't help. Took it to dealer and they said clutch needed
replaced, I knew that was BS. I discovered a few posts on this NG that
mentioned bad 02 sensors that would not trigger a CEL. I changed
upstream 02 sensor and BINGO, ran like new.

 

[Sheldon]

Sounds exactly like poblem I had with my '02 Forester at about 70,000
miles. I replaced plugs, wires, fuel filter, still had hesitation.
Took it to independant shop, they supposedly pulled injectors and
cleaned, didn't help. Took it to dealer and they said clutch needed
replaced, I knew that was BS. I discovered a few posts on this NG that
mentioned bad 02 sensors that would not trigger a CEL. I changed
upstream 02 sensor and BINGO, ran like new.

It's going in for an oil change on Monday. I'm going to let my mechanic
look into it. We decided to look for any hidden codes, and if we don't find
any dump some good cleaner in the gas tank and see what happens. I'll
definitely mention the O sensor.

He said if the engine has been stuttering it should show up in a code, but
not turn the CEL light on.