Throttle? MAP? Oxygen?

Okay, so I replaced the main relay all by my lonesome...never knew I was that limber! :) And then the check engine light came on...was told it was emissions related, but no clue. Have changed spark plugs (did you know the plug well can eat the socket sometimes? Yeah, who knew? And finally figured out how to get a new rotor on under the distributor cap (I'm learning all kinds of new things! Whoo-hoo!). It's still doing what it's been doing just not as badly: when I floor it to get on the highway, it hesitates and jerks and takes a moment or four to shift into gear. I have been told it's one of the three things listed above...but which one and how can I figure it out?

When you changed the main relay, did you reset the ECU? And after it came on again, did you try to reset it again? If it goes away after resetting, there may not really be a problem. Need to know what year and model and what code came up. I don't understand the plug eats the socket. Please clariify.

What and where is the ecu? How do I reset it?

I have a 91 Acoord LX. Her name is Lucky. Don't ask, will never tell.

The plug well eating the socket, okay, I suppose that would be user error then...everytime I would try to get the spark plug out after loosening, the socket would come off the ratchet. Had to use needle nose pliers to get the bugger out...

I'd suggest getting a nicer socket/extender then... One that locks into each other much better.

You can disconnect the battery for 15 seconds and then reconnect. You will lose your radio memory settings and clock time.