Hey folks,
Looking for some help diagnosing my sister's 01 Legacy. 244k, automatic, well maintained.
When accelerating, often times there's a noticeable drop in power. It's hard to explain, but it'll hesitate and bog and feel way down on power and then... poof, it runs perfect. It's a very definitive moment when the power returns to normal -- not a gradual increase, it'll be struggling one moment and all of a sudden it's running great. Cruising on the highway you can feel a very slightly surging.
I've checked for codes with FreeSSM on my laptop and there are none.
Things I've noticed:
- Coolant temp gauge never gets up to halfway -- sits around 175* F.
- Exhaust leak at flange between exhaust manifold and cat.
- TPS doesn't seem to report 100% -- when floored, it'd show 85%.
I haven't checked the PCV valve yet. Pulled the plug wires off the coils to check the condition of the posts and they were clean with some dielectric grease. I didn't pull plugs because it doesn't feel like a spark issue. Almost seems like a fuel delivery problem, but the fuel filter flows smoothly (took it out and blew through it -- no restriction). Haven't checked fuel pressure. The exhaust leak before the cat seems like a slam-dunk because it's just before the front o2 sensor, but the way it goes from running poorly to normal just doesn't seem like an exhaust leak.
Any thoughts? I realize this is a rambling post but I don't want to throw parts at it without some supporting diagnosis.
Looking for some help diagnosing my sister's 01 Legacy. 244k, automatic, well maintained.
When accelerating, often times there's a noticeable drop in power. It's hard to explain, but it'll hesitate and bog and feel way down on power and then... poof, it runs perfect. It's a very definitive moment when the power returns to normal -- not a gradual increase, it'll be struggling one moment and all of a sudden it's running great. Cruising on the highway you can feel a very slightly surging.
I've checked for codes with FreeSSM on my laptop and there are none.
Things I've noticed:
- Coolant temp gauge never gets up to halfway -- sits around 175* F.
- Exhaust leak at flange between exhaust manifold and cat.
- TPS doesn't seem to report 100% -- when floored, it'd show 85%.
I haven't checked the PCV valve yet. Pulled the plug wires off the coils to check the condition of the posts and they were clean with some dielectric grease. I didn't pull plugs because it doesn't feel like a spark issue. Almost seems like a fuel delivery problem, but the fuel filter flows smoothly (took it out and blew through it -- no restriction). Haven't checked fuel pressure. The exhaust leak before the cat seems like a slam-dunk because it's just before the front o2 sensor, but the way it goes from running poorly to normal just doesn't seem like an exhaust leak.
Any thoughts? I realize this is a rambling post but I don't want to throw parts at it without some supporting diagnosis.