Hi,
I have a Japanese imported 2001 legacy outback that i've owned for 3 years.
Over the last few months I have been trying to diagnose a problem that gives a symptom like the rule being restricted at part throttle cruse, more noticeable up hill with a steady foot. Engine speed 2500 rpm approx 60 miles per hour.
This makes the engine feel like its violently knocking on the engine mounts, the issue is more noticeable at a steady speed, but does have this this symptom during slower road speeds intermittently. Along with this when you floor it, the car seems to bog down, at random like it is in a too high gear, but moving the auto stick to a lower position doesn't effect the rpms (so its probably in the right gear).
I have done some troubleshooting via threads on this very useful forum, (a lot of good knowledge here).
Had a CEL for TPS so that was replaced.
Now occasionally CEL for P0171 bank 1 system lean when taken on long trips.
18 Mpg Average on combined city / highway.
The car:
2001 Subaru Legacy 3.0 H6 VDC Automatic
Japanese Domestic Market - it has no MAF sensor.
18-20 Mpg Average on combined city / highway.
128K miles
Trouble shooting so far:
Replaced the TPS with a new unit as has a CEL for it
Replaced the EGR valve
Replaced the IIACV
Spark plugs replaced with correct NGK ones
Air filter changed (paper type)
New battery 530 CCA
Vacuum lines have been checked (ends clamped down to reduce possibility of leaks)
O2 sensors positions swapped over to see if fault was with sensor or engine bank, but fault P0171 remained.
This problem comes and goes, disconnecting the battery helps it to drive more normally for 80 miles or so. Occasionally the VDC OFF light will appear for a few seconds while it misbehaves.
Starts usually first time, except for one instance 3 months ago where for some reason it just would not fire and then did.
Has anyone out here come across this before, or any idea where to look next. ?
Thanks.
I have a Japanese imported 2001 legacy outback that i've owned for 3 years.
Over the last few months I have been trying to diagnose a problem that gives a symptom like the rule being restricted at part throttle cruse, more noticeable up hill with a steady foot. Engine speed 2500 rpm approx 60 miles per hour.
This makes the engine feel like its violently knocking on the engine mounts, the issue is more noticeable at a steady speed, but does have this this symptom during slower road speeds intermittently. Along with this when you floor it, the car seems to bog down, at random like it is in a too high gear, but moving the auto stick to a lower position doesn't effect the rpms (so its probably in the right gear).
I have done some troubleshooting via threads on this very useful forum, (a lot of good knowledge here).
Had a CEL for TPS so that was replaced.
Now occasionally CEL for P0171 bank 1 system lean when taken on long trips.
18 Mpg Average on combined city / highway.
The car:
2001 Subaru Legacy 3.0 H6 VDC Automatic
Japanese Domestic Market - it has no MAF sensor.
18-20 Mpg Average on combined city / highway.
128K miles
Trouble shooting so far:
Replaced the TPS with a new unit as has a CEL for it
Replaced the EGR valve
Replaced the IIACV
Spark plugs replaced with correct NGK ones
Air filter changed (paper type)
New battery 530 CCA
Vacuum lines have been checked (ends clamped down to reduce possibility of leaks)
O2 sensors positions swapped over to see if fault was with sensor or engine bank, but fault P0171 remained.
This problem comes and goes, disconnecting the battery helps it to drive more normally for 80 miles or so. Occasionally the VDC OFF light will appear for a few seconds while it misbehaves.
Starts usually first time, except for one instance 3 months ago where for some reason it just would not fire and then did.
Has anyone out here come across this before, or any idea where to look next. ?
Thanks.