well actually the exception to the sensors Mike mentioned is the 95 DOHC neon which has a seperate IAT and MAP sensors....but he is right, as for the 420A coming in neons, it NEVER came in ANY neon, it did come in Avengers...but do not make the mistake of believing that the 420A engine is the same as the DOHC neon engine(which by the way is a D4RE, while the SOHC engine is a S4RE) the block on the 420A and the D4RE are the same, but the head is reversed, and the 420A uses weaker camshafts, and has in general different wiring and harnesses....but thats all beside the point and off topic, try to find out like FLneonRT said your AFRs throughout your boost range and if you can, your map sensor voltages as well to figure out whats going on