Subaru EJ22 issue

This just happened last night and I haven't had a chance to look at it yet, but I'm curious if anyone has any ideas of what to check.

I filled up my 96 outback with gas last night, and a few minutes after leaving the gas station it started running very rough and I could hear audible detonation when accelerating at any speed, and by the time I got home (I drove it about 2 miles since I first noticed an issue) it was running on 3 cylinders and had multiple misfire and cylinder #3 misfire codes.  I am thinking either a failed fuel injector or sensor, but does anyone have any other ideas?  I have a few extra injectors but it's about 10 days to get parts and I won't have much time to work on it until Friday so I'm hoping I can find the problem quickly.

Water in the gas?

They sell something to take care of water in gas if you think that might be the case. Might be worth a shot.

When did you last check your oil level? Mine liked to leak oil (I know, shocking) and if I let it go too long the hydraulic lifters would stop doing their job leading to bad noises and the knock sensor kicking in and pulling all the timing. Every time it happened I'd top it up and within the next 25-50 km everything would smooth back out and run fine again. With your check engine light and code this may not be the case but it's pretty easy to check so worth doing if the hood is up.

Any chance you filled it with diesel?

I will check the oil again, but this is a fairly low mileage engine and its from a 98 so it has solid lifters.  I have put close to 40k miles on this engine and it has ~98k when I put it in.  The car has 489k on it though.  I know I didn't fill it from a diesel pump, because a diesel nozzle won't fit in a gas car, and I was on the opposite side of the gas station from where the diesel pumps are when I filled it up anyway.  I checked the spark plugs and the #3 plug was slightly loose so I re-torqued them all (I tightened them with a torque wrench when I installed them originally), but it still runs too rough to be drivable.  The loud detonation sound when trying to accelerate at all makes me thing something else is wrong, but I'm going to try new plugs and see if it changes anything.  All the terminal ends pulled off the wires when I took them off to check the plugs, so I put an old set on that I know worked when I took them off too.

In reply to Tk8398 :

That's incorrect. There are 2 different sized diesel pump nozzles at most stations, and there are lots of small passenger vehicles that take diesel with the smaller nozzle.
 

If you were at a BP station, they reverse the colors on the pump handles. Green is gas (most stations green is diesel). Ask me how I know. ..

Double check your receipt. What you are describing is exactly what diesel would have done. 

For sure not diesel unless it was the gas stations fault, but it didn't smell like it either.  I have a diesel car too so definitely pay attention, and I filled it up at a different pump island than the ones that have diesel at that station.

The reciept definitely says regular unleaded which is what it's supposed to be, and the fuel that's in it doesn't smell like diesel.  I tried changing the coil pack and cam position sensor (since I had extras), and no change.  I also checked all the vaccum lines and plugged the brake booster hose to see if that made a difference but no change.  Is there any other way to tell if the fuel is bad? I think something just happened to break at the same time but it's suspicious that it happened right as I left the gas station.

Well, you could drain the tank. Pretty sure this vehicle doesn't have a drain plug, I had a 98 outback. Could drain the tank by hotwiring the fuel pump so it stays on and run a hose from the underhood fuel filter to a gas can. It might be a good idea to just eliminate fuel as a variable.  Get the gas out, get some fresh gas in, if it doesn't fix it you can cross that off your list as a potential issue. 

Could the "detonation" really be rod knock? Could it have jumped time? EJ22s were known for shearing the woodruff key that goes to the crank pulley and in some cases the sprocket for the T-belt can be effected too. Check the crank pulley for wobble. The nut that holds the crank pulley on works loose at the original specced torque (they revised it upwards later) and then sets a cycle of destruction in motion. 

SVreX (Forum Supporter) said:

In reply to Tk8398 :

If you were at a BP station, they reverse the colors on the pump handles. Green is gas (most stations green is diesel).

That drives me berking insane.  I often use BP stations because you're sure to get Top Tier gas there and I have an internal rant about that every time I fill up.

I will also agree that it sounds a lot like you accidentally put diesel in it.  A friend's husband put diesel in her CR-V and it behaved exactly like that.  I will, however, take your word that you did not.

In reply to Duke :

I share your misery on that particular rant. It was even worse when I drove a diesel. Ended up with a tankful of gasoline 2 separate times just because some marketing pro at BP is apparently colorblind. 
 

Rant off. 

Are diesel pumps only disgusting in Florida? Every time I take my wife's diesel and I have to put diesel in it the pumps are filthy with caked up brown oil. No matter the brand. 

I am 100% sure I used the right pump, what came out of it idk but it seemed like gasoline to me.  Of course the spark plugs I ordered showed up with only one in the box not 4, so I have to find another place to get them or reorder.

Turns out one of the 4 cylinders wasn't getting spark, I must have accidentally put the same coil pack back on but I replaced it and it's fine now.

Great news!