95 Protege 1.5 DOHC maintenance question

[rrhyne56]

Son has a 95 DOHC 1.5 Protege. It is intermittently running rough, check engine light comes and goes, I figure we ought to start replacing O2 sensors, etc. etc. just to cover all the bases.

What are the main culprits, the ones that ought to be looked at for replacement in a general course of maintenance?

 

[JReichle1]

Get a computer diagnostic first instead of just throwing money at it. If you want to start somewhere check the air intake between the air filter and the throttle body. Over time the rubber cracks and tears allowing unmetered air into the intake. This will cause the car to run rough and possibly turn off. These hoses are a weak point and a good starting place. If that dosent solve the problem try replacing the spark plugs and wires.