I’ve been having a lot of problems with my 03 Subaru Outback lately as I am a rural carrier in North Dakota, the gravel and weather really take a toll on my car. I am no car expert either, I can change the oil and a flat tire, and that’s about it. That said, I have been using another car to save this one for winter, but I recently had to use it for a small blizzard we had. When switching back to my spare car, I accidentally left a light on and drained the battery. My family has one of those automatic battery rechargers and I charged it back up. When I started it up, I turned it off and it had a weird shuddering for like 2 seconds that wasn’t there before, well not as strong at least. I turned the car on and off again a few times and the shuddering was still there. When I got out, I noticed a really strong gas smell.
Last time I was at the mechanic, he said my catalytic converter was bad but that I didn’t need to replace it because the outbacks had them go bad all the time and could go years with bad ones. Could my drained battery somehow have affected something fuel related and ruined the converter, or pushed it over the edge? Completely unrelated? I started the car in a garage with the door open in cold weather (below freezing I think). Maybe the cold weather just accentuated the gas smell? What about the shaking? Any ideas? I have been getting work done on this to prepare for winter, but more things seem to keep going wrong. Thanks for any help.
Bring it into a local parts store and ask if they could check the battery and charging circuit. Many will do this for free. It may well find the problem, or if not find your current problem, it may find a weak point that may need to repaired now to avoid a breakdown later.
Good Luck
It’s cold outside.
You’re starting the car (which is running rich because of the cold) and then shutting it off right away.
Stop doing that. You’re flooding the cylinders with raw gasoline, which is not good.
If you’re going to start the engine, let it run long enough to warm up.
The drained battery shouldn’t have affected anything else.
Is the Check Engine Light on? How long has it been on?
Because it only shook for a few second after start-up, it sounds to me like maybe it was misfiring. When was the last time it was tuned up?
If your battery was dead for a while then I wouldn’t pay much attention to small aberrations in the way the car runs for a couple hundred miles or so. The computer probably lost its memory. It has to start everything at default values and then “relearn” everything as it runs and drives for a while. There is also a good chance that your fuel lines may have been mostly empty of fuel after sitting that long. Somewhat odd behavior is not too surprising.
If the engine light starts flashing at you, then you should worry. If the engine light does come on at all have the car scanned for error codes.
The gas smell, as mcparadise said, is likely just from you starting/shutting down with a cold engine. This will tend to flood things.
All of that, however, is based on the assumption that basic things like spark plugs, wires, filters, etc. are all in good shape.
The same thing happened to me, maybe 3 years ago? I have a 96 outback legacy, and it would rumble and bounce when started, and belch a huge amount of wet, gassy smoke out the exhaust for the first few seconds. What ended up being broken was one of the valves in the fuel injection system, allowing gas to pool in the engine (extra combustion forces a cloud out the tailpipe and the rumble up front). I don’t remember it being a hugely expensive fix. If you’re in Grand Forks, the dealership on Gateway did a good job (their hourly rate has gotten ridiculous though). Mine has one cylinder that regularly misfires if I force it to move before it’s totally warm (in January in ND this can take 15-20 min)it does suck up gas, not burn it and then spit it out the exhaust, but so far hasn’t caused major problems. Also, my outback was a mom car before, and when I started driving it I found out that the catalytic converters had been broken for years, it still ran just fine. Hope this helps!