My Check engine light comes on when im going down the highway doing 70 if i go up to 75-80 the light goes off and just driving around town it is off went and had the codes pulled and got code 176 and 172 saying bank 1 & 2 are Lean what could be causing this? It is a 1994

it usually means both o2 sensors are no longer good. have you checked them out with a dvom?

That does not mean your O2's are bad, IT MEANS THE CAR IS LEAN!!! just what it says. I would check for vacuum leaks, check the pcv tubes hoses and the T on the back side of the engine on the drivers side, I would also clean the Mass air flow sensor with a que-tip and brake clean.

Im not sure how to go about cleaning the Mass air flow sensor but i think this is what i need to do did not find any vacuum leaks. any step by step on the cleaning of the Mass air flow sensor in a Tech article somewhere?

That does not mean your O2's are bad, IT MEANS THE CAR IS LEAN!!! just what it says. I would check for vacuum leaks, check the pcv tubes hoses and the T on the back side of the engine on the drivers side, I would also clean the Mass air flow sensor with a que-tip and brake clean.

Actually I found that windex works better then break kleen, but start with clening that. How's your air fillter?