2002 Ranger; vibration/check engine light

[Popz]

This problem developed tonight as I was coming back from the store and pulling in my driveway. The truck started 'chugging' almost, somewhat hard vibrations spaced apart by about 1 second or so.

If I gas it above 1.5-2K rpms or so you can hear a rather loud metalic rattle eminating, it seems, from the bottom of the vehicle.

It will go into gear and accelerate, the transmission seems fine as the gear shifts are as smooth as they have ever been. Once under power and moving it doesn't 'chug' (so to speak), but the engine feels less responsive. The check engine light came on after I drove it for about .5 miles or so.

What could be causing this? (49K miles, if anyone is wondering)

 

[Popz]

Oh, I should also add that there seems to be a dis-proportionate amount of exhaust with an almost sweet smell to it. It's kind of foggy tonight, so I'm not sure if that's another symptom or not.

 

[Old As Dirt]

Did you gas up at the "store"? Sounds like bad fuel.

 

[Popz]

i didn't get gas the night it started happening, but i had gotten about 5 gallons or so a couple of days before.

my uncle and i took a look at the truck earlier in the day and he concurred with that- that it's probably bad gasoline. i'm thinking this sounds reasonable given that the rpms at idle flux between 400-600 rather than remaining fairly steady around 500 as it usually would.

there are a couple of things that boggle me though. for one, there's the metallic tat-a-tat-a-tat-a-tat sound that occassionally comes up as the rpms increase, and the second is that it's such a pronounced overall effect.

i'm assuming that the gas is causing... i suppose misfires would be the word, which in turn causes the more marked engine vibration, which in turn is causing the muffler to bounce rapidly- which would account for that loud tat-tat-tat-tat sound.



i'm already a fairly anxious person, and to top it off i'm broke. is this something a bottle of injector cleaner and a fresh tank of gas can fix or am i looking at needing to take it to a shop (since i have neither the time nor tools to do the repairs?)