So this all started with a Camshaft position sensor code. While driving (freeway or not), randomly the engine would run rough and with my exhaust it sounded like a Subaru engine. Sometimes it wouldn't happen for maybe 20 miles and then happen for only 2 minutes then go away. When it happens the shifter would vibrate really bad.

I replaced both sensors and while I was in the mood, replaced the crankshaft position sensor too. Unplugged my battery for a bit to reset the CEL. The car drove fine for the rest of the day.

The next day, I started her up and almost immediately while idling- engine was idling rough and again the exhaust sounded like a Subaru. Also I noticed under the engine bay the entire motor had lots of vibrations. No codes in 50 miles and I can't figure out why it's doing this.

What else could this be?

tl;dr

- Rough idle
- Had code for Camshaft position sensor
- Replaced both sensors and the crankshaft sensor under the tranny.
- Rough idle went away for that day and came back the next
- No more CEL but still really rough and lots of vibrations
- Engine seems to rock
- Reving the engine makes the shifter shake like mad

 

Really sounds like a misfire but that would certainly throw a CEL. Does the light still come on when you just turn the key to the on position? Even if it's not throwing the light you might check and see if there are any codes pending.

 

Hmmm, so what would start causing a misfire? When I turn my key to the position just before it starts the car my SES light turns on and after I start it immediately turns off.

I took the car around the neighborhood today and noticed as the engine warmed up more I'd get less rough idle/acceleration. But it's really sporadic, sometimes I could be driving in 3rd going straight (no hills) and it would be normal and then suddenly I get loss of power and hesitation with lots of shaking in the shifter. More gas just makes it sound like then engine's off balance or not firing a cyl (or 2). Then suddenly will go back to sounding and driving like normal.

Odd problem I'm having.

 

A bad coil pack won't always throw a code, so I'd check any ignition problems as you have fuel and air aplenty. Start with the plugs and work your way upward. Pull a coil while the car's running okay and see if it sounds the exact same way as you described in your post. If it is then you've found it.

 

I'm sorry to bring back an old post but this is the exact problem I'm having. Eyesea did you ever figure out what the problem was?

Thank you so much!

 

My car just started doing this same thing today. I initially thought my exhaust sounded like a Subaru too. Did OP fix it? Or does anyone else know what the cause/issue might be?

 

I did end up fixing it. Turned out to be a bad coil pack. I tested this by disconnecting 1 at a time while the engine was running.

 

Fixed mine today, it was a bad coil pack. Here's how I found it:

The motor still sounded like a WRX. while running, I disconnected a coil pack at a time. When I took one off, I noticed the motor bogged down for a second, then went right back to the wrx sound. When I came across the bad coil pack and disconnected it, the sound of the motor didn't change at all and it didn't bog down.

That's how I knew it was the bad one. Hope this helps.