stumbling/hesitation on highway...

[superstock2]

my car is a 1994 touring wagon, and in town it runs great. the problem is when i get on the highway the car will run ok and then when i get to around 80 mph it starts to run like ass.. sometimes the check engine light will come on too. i'm not new to cars, just to piston engines and subies... anyhelp is appreciated, especially since i need to take the car on a 200 mile road trip here in the next month.
Tony

[Legacy777]

Check the ECU for the codes since the CEL is coming on. Instructions are on my site.

www.surrealmirage.com/subaru/engine.html

post back with the codes when you get them.

[superstock2]

sorry for the wait... it looks as if it is throwing code # 41?
A/F learning contro: Faulty learning control function
what does this mean

[Legacy777]

Probably an issue with the ECU.

I'd suggest resetting the ECU and see if that helps, and see if the code comes back.