So my 86 has 180 000 km's, before I got it it had been sitting for a long time apparently.. It's been used quite a bit since then (few thousand km). Today I did a oil change, replaced the air and fuel filter, all new wires and new plugs. The problem is still there though


When I start it it runs a little rough, which usually clears in 5 mind or so, than about 10 min later the check engine light comes on, the revs drop about 300 and it runs little more rough again. This happens intermittently while driving as well and feels as though it has less power when it's check engine is up.

Old plugs were caked with white, so I'm thinking it could be injectors, maf sensor or oxygen sensor? Could an exhaust leak cause this as well?

Any ideas or other possibilities? Preferably cheaper ones first!

Thanks!