I just went to Autozone to get my SES light checked out, and it put out code 34 which is low voltage for the MAP sensor. I'm about to test the sensor.
The only problem is, I checked in the book and it said there could be a host of other things wrong ranging from a malfunctioing vacuum line to a bad ECU.
So I have 2 questions:
1. Has anyone else ever had a code 34?? Is it usually JUST a bad MAP sensor??????
2. Which vacuum line do I check? There's a big one by the air intake that came off. What is the significance of that line?

 

What would be next step after replacing the MAP sensor??

 

The MAP sensor requires a +5V reference signal from the PCM. Did you verify that signal was present at the harness connector? Did you measure MAP: voltage and indicated MAP kPa (or "Hg) at idle, under moderate load, and at WOT? What values are you getting?

 

Since the MAP sensor was in bad shape (oil residue around vacuum line and wiring harness) I just changed the MAP sensor ($34 at Autozone) and so far all is well!