Is the Evaporative Emission System Pressure Sensor inside the gas tank or on top of the gas tank

SOURCE: what P0453-Evaporative Emission control System Pressure Sensor h

P0453 is for the fuel tank pressure sensor. This code means that the voltage on the sensor was greater than 4.5V during key on engine off or during any engine operating mode.
Normal voltage from this sensor with no vacuum or pressure on the system should be 2.37 to 2.97V.
PCM sends a reference voltage of 5V to the sensor and tells if there is pressure or vacuum in the fuel tank by the voltage that returns from the sensor.

Possible causes are:

Harvey N Tawatao

• 3854 Answers
• Posted on Apr 09, 2009

SOURCE: 1998 PONTIAC SUNFIRE ADVISE

Exhaust Gas Recirculation System Is the main problem here. the other code P0118 may be a bad temprature sensor or your thermostate needs to be changed. Last it could be a weak water pump. 

So what is an EGR system and how does it work? EGR stands for Exhaust Gas Recirculation, and as its name implies, this system allows exhaust gasses from your car to be re-circulated into the engine, helping to reduce emissions. These systems are mostly comprised of the EGR valve, a DPFE (Delta Pressure Feedback EGR) sensor, hoses, a vacuum regulator, some vacuum lines, wiring, the computer and the exhaust tube leading to the valve itself. 
The car's wiring can be tested in the normal fashion by looking for broken and lose wire, and all vacuum lines can be checked easily for cracks, leaks and correct routing.
The last thing i would then check is the the EGR valve, EGR vacuum regulator and DPFE sensor (or similar flow sensor).
I hope this helps and good luck

SOURCE: Im trying to locate the Evaporative emission

It is built onto the fuel pump. You can access the fuel pump in the trunk under the carpet. Remove the bolts from the rectangular cover and it is the black sensor pushed into the fuel pump housing.

Colin Stickland

• 22516 Answers
• Posted on Mar 20, 2011

SOURCE: P0452 Evaporative Emission Control System

if you check the rubber pipes from the inlet manifold you will find that one of them is perished or cracked so its losing vacumn.,then check the return one to the fuel tank as well just for good measure

SOURCE: OBDll code p0452, Evaporative Emission System pressure sensor/switch low input, what does this mean

Your Charcoal Evap filter is dirty.
Clean it or replace it (some cars can be simply cleaned - some cannot).
It is located in the engine compart,ment (you will have to consult the owner's/service manual to find out exact;y where it is).
..
Note: Sometimes this code can be driven by a bad gas cap seal as well - so don't forget to check that the gas cap is good).