My friend has a 87 Vette and it has a code 33 and 34. The MAF voltages look fine on my scanner but the MAP sensor voltages dont move when you rev or drive the car. I know that if a car has a MAF it wont have a MAP sensor so what is sencing the MAP voltage? The only thing I could think of is the Charcoal canister. Is it possible that the Charcoal canister sences Manifold Absolute Pressure and might be bad?

 

If there's a MAF, then there is no MAP. You might have a generic scanner that shows PIDs that aren't supported by certain systems. Surefire way to tell is to plug it into a car with a map and see if it still shows that there's a MAF.

 

2_point8_boy ur right man.....maf means no map...89TA383M5 try to find the real part of that you call MAP sensor....maybe is it the TPS sensor since your talkin about voltages....

 

My scanner fried and they hardly ever drive the car so when i get another scanner I'll investigate further. The whole thing confuses me.

 

tell him to check for holes or cracks after the sensor and ensure all ducting is properly connected and tightened.