ANY CLUE?: Sputtering, hesitating, stalling, bucking, almost no power // Engine light on?

Yesterday our 98 Subaru Outback was fine. This morning, engine light is on and the car is sputtering and bucking. Going 1 mile an hour with seemingly zero power, then suddenly lurching forward. The stalling is only because it’s so slow and powerless, e.g. going up an incline. I managed to put and sputter to the garage and left it there, without speculating. Can someone please give me a few clues as to what it might be? I have spent $7K on my car in 7 months and have no savings left to cover a big repair. Feeling really anxious.


First, some questions:

  1. Last time plugs and filters were changed out?
  2. Is this condition only on incline or now all the time?
  3. Can you get the check engine light code read and post it here; it will provide insights as to what the issue is?

Yes, no point in guessing. The first step should be to pull the codes set in the onboard diagnostic computer.

We had a tune up this year. a few months ago. My records aren’t in my office at the moment, but it was reasonably recent. … The condition is all the time, but it comes and goes when the street is flat. Becomes a crisis when it’s an incline. I would have no idea where to find a code for the engine light. It’s an old car and nothing is digital. The car is at the shop so I can’t consult the book. sigh.

My car has a manual dash… I don’t think there’s any diagnostic computer in the car. The mechanic would have to hook one up. Unless I’m just totally unaware. I know guessing seems futile, but if I at least know the possibilities, I might be more prepared. I hate to cancel business meetings and sell assets in an emergency frenzy. Which is what would happen if I need a new engine. Just trying to find out what it could be, even if it’s a few things…sigh. Thank you for the reply.

First thing I’d check with symptoms like that is the mass air flow sensor. Give it a wrap with the handle of a screwdriver and see if it changes anything. But the garage already has it.

Thank you. So… not necessarily a blown up engine? That’s one thing I wanted to know. So these replies may be vague, but it helps to know it could be something not too horrible.

If it was running fine recently, there is nothing wrong with it that can’t be fixed, but of course nothing is free (or cheap). I wouldn’t suspect a sensor as much as I’d start looking at the electric fuel pump in the tank. That’d be my first place to start. I’m guessing a 400-500 repair if that was the case. The pump itself might sell for 150 bucks, and the rest are labor. That is if it is the fuel pump. We do need to go on for better troubleshooting ideas.

Perhaps you live in a country other than the USA. I forgot to ask. If in the USA, all cars sold since 1996 are required to have the OBD II system. When the check engine light comes on, one or more diagnostic codes are set in the computer. By retrieving them the problem area can be narrowed down so you don’t waste time and money looking at the wrong areas. I realize you don’t have a code reader and getting your vehicle to a shop that has one could be a problem. If there is an Autozone parts store near you, call them to see if they can pull the codes for you. Most do. Maybe you can get there and back.

Well, the frist thing I would suspect is a sensor. The mass air flow sensor or heated O2 sensor will both send signals back to the computer and alter the fuel mixture causing your symtoms. These will set off the check engine light, a fuel pump will not. It’ll take about two seconds to chase this down with a diagnostic code reader. Ten year old car is about where they start to fail.


There could be a few repair attempts while trying to solve the problem. It may not happen that way and the car could be fixed on the first try. If it isn’t fixed after a few tries, the engine computer could be bad. Your problem could be due to a simple defective component so I wish you luck. It could also be a throttle position sensor that has failed.

I have a 99 Outback that had a similar, albeit less severe, hesitation. No check engine light, but a new O2 sensor made the problem go away (a MAF did not fix the problem, but fortunately my shop didn’t charge me for that). At the outset they tried new plugs and wires, but that didn’t solve the bucking. Unfortunately, it took a while to diagnose.

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here. 

Regarding warning lights:

  1. if the coolant temp light comes on, shut off the engine ASAP

  2. if the oil warning light comes on, shut off the engine ASAP

  3. if a FLASHING MIL/CEL comes on, shut off the engine ASAP

    ASAP means driving to the berm of the highway right now and not waiting for the next exit.

But if the MIL/CEL is not flashing, then it’s not an urgent indicator.