It depends on the engine size. Most are located on the intake manifold.
There is one before the catalytic converter and one after.
That would depend on which model year of Chevrolet Malibu ( both rear wheel drive and front wheel drive versions have been made )
The VSS (Vehicle Speed Sensor) would be found on the right rear of automatic transmission or transfer case. If it is a standard it would be found on the left rear of the transmission.
bad ground
The coldness
The model year would help. Chevrolet has been building the Malibu from 1964 to 1983 and then again from 1997 to present.
the sensor is located in the front of the car when u open the hood it should be to the left of the hood latch.Its a small looking sensor with only 2 wires on the plug. The sensor costs only $8.00 at your local dealer.
The dye was put in the system to tell where the leak is located. Return to the repair shop and let the check it out.
It would be to your advantage to buy a Haynes Manual as there is plenty of information that would be very helpful.
That would depend on the year and engine size. If you do not see a distributor then it is distributorless ignition.
A faulty crank sensor would cause no spark and no fuel.
Did this to my 98 Malibu v6, the low pressure valve is on line beside fire wall behind engine, it has blue protective cap on it. high pressure valve you would not use has red cap on it located beside radiator/condenser. You don't say what year your Malibu is so this may not apply to you if your unit uses the R12 refrigerant.