Did chevy make a single line fuel pump for a small block

440 code is the evap vapor system failure and the 1675 is an error code for the solenoid that controls that system, IT appears they are related. If you did any maintenance on the vehicle you may have knocked a connector loose. If you did not have any maintenance done then it would be a solenoid valve or cable / connector failure

What engine does it have ?
Engine Controls - 4.3L
Engine Controls - 4.8L, 5.3L, and 6.0L
DTC P0440 Evaporative Emission (EVAP) System
Circuit Description
The evaporative system includes the following components:
• The fuel tank
• The evaporative emission (EVAP) vent solenoid
• The fuel tank pressure sensor
• The fuel pipes and hoses
• The vapor lines
• The fuel cap
• The evaporative emission canister
• The purge lines
• The EVAP purge solenoid
The evaporative leak detection diagnostic strategy is based on applying a vacuum to the EVAP system and monitoring the vacuum decay rate. The vehicle control module (VCM) monitors the vacuum level via the fuel tank pressure sensor input. At an appropriate time, the EVAP purge solenoid and the EVAP vent solenoid turn ON, allowing the engine vacuum to draw a small vacuum on the entire evaporative emission system. If a sufficient vacuum level cannot be achieved, a large leak or a malfunctioning EVAP purge solenoid is indicated. The following conditions can cause this problem:
• A disconnected or malfunctioning fuel tank pressure sensor
• A missing, malfunctioning, improperly installed, or loose fuel cap
• A disconnected, damaged, pinched, or blocked EVAP purge line
• A disconnected or damaged EVAP vent hose
• A disconnected, damaged, pinched, or blocked fuel tank vapor line
• A disconnected or malfunctioning EVAP purge solenoid
• A disconnected or malfunctioning EVAP vent solenoid
• An open ignition feed circuit to the EVAP vent or purge solenoid
• A damaged EVAP canister
• A leaking fuel sender assembly O-ring
• A leaking fuel tank or fuel filler neck
Any of the above conditions can set a DTC P0440.

This is what it looks like and it is located in the gas tank:



First, you'll need to use up as much fuel as possibly, if not, you'll have to drain the tank. Next:

1. Drain the fuel tank.
   
2. Support the fuel tank.
   

1. Remove or disconnect the following:
2. Negative battery cable

• Filler neck from the tank
  
• Shield from tank and tank straps
  
• Fuel lines and vapor hose from pump
  
• Electrical connection from fuel pump
  
• Fuel tank
  
• Fuel pump/sending unit assembly by turning the locking ring (located on top of the fuel tank) counterclockwise using a spanner wrench
  
• Fuel pump from the fuel lever sending device
  

NOTE
The fuel pump strainer must be in a horizontal position when the fuel sender is installed in the tank. When installing the sender assembly, make sure that the fuel pump strainer does not block full travel of the float arm.

To install:

1. Install or connect the following:
   
   • Fuel pump in tank with new seal around opening
     
   
   NOTE

   The fuel pump strainer must be in a horizontal position when the fuel sender is installed in the tank. When installing the sender assembly, make sure that the fuel pump strainer does not block full travel of the float arm.
   
   

   • Tank and connect fuel lines and vapor hose
     
   • Tank to the frame. Torque the fasteners to 33 ft. lbs. (45 Nm).
     
   • Shield
     
   • Fuel filler neck and clamp
     
   • Negative battery cable
     
2. Refill the tank.
   
3. Run the engine and check for leaks.
   

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their are two fuel line at the front of the tank one is the fuel feed and the other is the return line! Now the ones at the back of the tank are for emission you don't want to break or damage those make sure you disconnect all of those line and the is a red connector also at the rear of the top of the tank make sure you disconnect that. And just make sure careful when remove fuel pump it has a tight fit coming out also when your done make sure all your hoses and lines are reconnected and the red ont too! GOOD LUCK !

The evaporative leak detection diagnostic strategy is based on applying a vacuum to the EVAP system and monitoring the vacuum decay rate. The VCM monitors the vacuum level via the fuel tank pressure sensor input. At an appropriate time, the EVAP purge solenoid and the EVAP vent solenoid turn ON, allowing the engine vacuum to draw a small vacuum on the entire evaporative emission system. If a sufficient vacuum level cannot be achieved, a large leak or an EVAP system malfunction is indicated.

The following conditions can cause this problem:
* A disconnected or malfunctioning fuel tank pressure sensor
* A missing, malfunctioning, improperly installed, or loose fuel cap
* A disconnected, damaged, pinched, or blocked EVAP purge line
* A disconnected or damaged EVAP vent hose
* A disconnected, damaged, pinched, or blocked fuel tank vapor line
* A disconnected or malfunctioning EVAP purge solenoid
* A disconnected or malfunctioning EVAP vent solenoid
* An open ignition feed circuit to the EVAP vent or purge solenoid
* A damaged EVAP canister
* A leaking fuel sender assembly O-ring
* A leaking fuel tank or fuel filler neck

Any of the above conditions can set a DTC P0440.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

Fuel Tank Assembly Removal & Installation Single Tank To Remove:

1. Before servicing the vehicle refer to the precautions at the beginning of this section
2. Relieve fuel system pressure (See: Fuel System Relieving)
3. Disconnect the negative battery cable
4. Raise and support the vehicle
5. Drain the fuel tank in an approved container
6. Remove or disconnect the following:
   • evaporative emission (EVAP) canister Disconnect fuel lines for single tank
     
     
   • Chassis fuel lines (B) at the fuel tank (A)
     1. Cap the fuel and EVAP lines to prevent possible fuel system contamination
     Disconnect EVAP vent line
     
     
   • EVAP vent line at the fuel tank clip (E) Disconnect vent hose and filler hose
     
     
   • Vent hose and filler hose clamp (D, B)
   • Vent hose and filler hose from the line
   Fuel tank removal
   
   
7. With the aid of an assistant or a suitable jack support the fuel tank
8. Remove or disconnect the following:
   • Fuel tank strap attaching bolts
   • Fuel tank straps
9. Carefully lower the rear of the fuel tank slightly
10. Remove or disconnect the following:
    • Fuel sender cover Fuel tank connections
      
      
    • Fuel sender and the fuel pressure sensor electrical connectors
    • Fuel tank
11. Place the fuel tank in a suitable work area Fuel lines at the tank
    
    
12. Remove or disconnect the following:
    • Fuel feed and return lines (C) from the fuel sender and the retaining clips
    • Fuel pump assembly from the fuel tank
    • EVAP line from the fuel tank roll over valves (B, D) and the retaining clips (A)
    • Fuel fill hose and the vent hose from the fuel tank
    • Fuel tank

To Install:

1. Install or connect the following:
   • EVAP line to the fuel tank roll over valves and the retaining clips
   • Fuel pump assembly to the fuel tank
   • Fuel feed and return lines to the fuel sender and the retaining clips
   • Fuel fill hose and the vent hose to the fuel tank; torque hose clamps,
     1. Torque to: 22 lb-in. (2.5 Nm)
2. With the aid of an assistant or a suitable jack support and partially raise the fuel tank front end first
3. Install or connect the following:
   • Fuel sender and the fuel pressure sensor electrical connectors
   • Fuel sender cover
4. Fully raise the fuel tank
5. Install or connect the following:
   • Fuel tank straps
   • Install the fuel tank strap attaching bolts;
     1. Torque to 30 lb-ft. (40 Nm)
   • Fuel fill hose and the vent hose to the lines;
     1. Torque hose clamp to 22 lb-in. (2.5 Nm)
6. Torque the vent hose clamp,
   • Torque to: 22 lb-in. (2.5 Nm)
7. Connect the EVAP vent line to the fuel tank clip
8. Remove the caps from the fuel and EVAP lines
9. Install or connect the following:
   • chassis fuel lines at the fuel tank
   • EVAP canister
10. Lower the vehicle to the ground
11. Fill the fuel tank with clean fuel
12. Install the fuel filler cap
13. Connect the negative battery cable
14. Use the following procedure to inspect for leaks:
    • Turn the ignition on for two seconds
    • Turn the ignition off for 10 seconds
    • Turn the ignition on
    • Inspect for fuel leaks
15. Install the engine sight shield
16. Road test the vehicle to check performance

The fuel pressure regulator is built in to the fuel pump


Fuel tank and fuel pump assembly—XG 300

1. Before servicing the vehicle, refer to the Precautions section.
   
2. Relieve the fuel system pressure.
   
3. Drain the fuel tank.
   
4. Remove or disconnect the following:
   
   • Negative battery cable
     
   • Fuel supply, return and vapor lines
     
   • Fuel fill and vent hoses
     
   • Fuel pump module connector
     
   • Fuel level sender connector
     
   • Fuel tank straps
     
   • Fuel tank
     
   • Fuel pump module
     

To install:

1. Install or connect the following:
   
   • Fuel pump module and torque the mounting bolts to 12–24 inch lbs. (1–3 Nm)
     
   • Fuel tank
     
   • Fuel tank straps
     
   • Fuel level sender connector
     
   • Fuel pump module connector
     
   • Fuel fill and vent hoses
     
   • Fuel supply, return and vapor lines
     
   • Negative battery cable
     
2. Fill the tank with fuel and check for proper fuel pump operation.
   

First you should check your trunk. some newer chevy's have an access pannel uner the trunk liner inside the trunk. you remove the liner, remove the bolts and panel, and the pump is right there. it may take some effort to get it wiggled through, but trust me, it will fit. you must remove the fuel lines and wire harness first, then remove the lock ring completely before attempting to pull the pump through the access hole. if that fails then you need to drop you fuel tank to access the pump. there are instructions for removal and installation of the tank below.

REMOVAL & INSTALLATION

1. Disconnect the negative battery cable.
2. Drain the fuel tank, using a hand-operated pump device to drain as much fuel through the filler tube as possible.

Fig. View of fuel tank mounting


Fig. The fuel filler pipe is attached to the body with a bracket and retaining bolt


Fig. The fuel filler pipe is attach to the tank by a hose clamp

1. Raise and safely support the vehicle.
2. Unfasten the muffler hanger bolts.
3. Remove the rubber exhaust hangers, then allow the exhaust system to rest on the rear axle.
4. Disconnect the hoses from the fuel tank sender. Grasp the filter and one nylon fuel connection line fitting. Twist the quick-connect fitting 1 / 4 turn in each direction to loosen any dirt within the fitting. Repeat for the other fitting. Using compressed air, blow out the dirt from the quick-connect fittings at the end of the fuel filter.
5. Detach the quick-connect fittings by pulling the release tabs back on the fuel line quick connector and pulling apart.
6. Disconnect the hoses at the tank from the filler, vent and vapor pipes.
7. With the help of an assistant, support the fuel tank, then disconnect the two tank retaining straps and carefully lower the tank.
8. Detach the fuel sender electrical connector.
9. Unplug the fuel pressure sensor connector.
10. Remove the fuel tank from the vehicle.

To install:

1. If the tank is being replaced, perform the following:
   1. Remove the sound insulators.
   2. Remove the modular fuel pump/sender assembly, as outlined earlier in this section.
   3. Inspect all connectors for dirt and burrs. Clean or replace, as required. Inspect the fuel line O-rings for cuts, nicks, swelling and/or distortion and replace as necessary.
   4. Install the fuel sender assembly to the new tank, as outlined earlier in this section.
   5. Install the sound insulators.
   
   
2. With the help of an assistant, raise the fuel tank to the vehicle and attach the fuel sender connector and, if equipped, the fuel pressure sensor connector.
3. Raise the fuel tank into position then fasten the retaining straps. Tighten the retaining bolts to 26 ft. lbs. (35 Nm).
4. Connect the hoses to the filler, vent and vapor pipes.
5. Attach the nylon fuel feed and return connecting line quick-connect fittings to the fuel sender, as follows:
   1. Apply a few drops of clean engine oil to the male connector tube ends.
   2. Push the connectors together to cause the retaining tabs/fingers to snap into place.
   3. Once installed, pull on both ends of each connection to be sure they are secure.
   
   
6. Install the rubber exhaust hangers.
7. Install the muffler hanger bolts, then tighten to 11 ft. lbs. (15 Nm).
8. Attach the fuel tank sender electrical connector.
9. Carefully lower the vehicle.
10. Refill the fuel tank, then connect the negative battery cable.
11. Turn the ignition to the ON position for two seconds, then turn it to the OFF position for ten seconds. Turn again to the ON position and check for fuel leaks.

The fuel pump and sending unit is located in the tank. I hope your tank is empty, if not you will need to siphon it out. It is dangerous with the gasoline, and remember the fumes burn, not gas. You start by removing the filler hose, then loosen straps, detach sending unit wire and fuel line, then lower tank. Then unscrew the sending unit/pump and replace. reinstall.

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c152801dbaf3

when you drop the tank by following these directions you will have access to the pump

1989-94 Vehicles
See Figures 1 and 2

1. Disconnect the negative battery cable.
2. Properly relieve the fuel system pressure, as outlined earlier in this section.
3. Raise and safely support the vehicle.

CAUTION Observe all applicable safety precautions when working around gasoline. Do not allow fuel spray or fuel vapors to come in contact with a spark or open flame. Keep a dry chemical (Class B) fire extinguisher near the work area. Never drain or store fuel in an open container due to the possibility of fire or explosion.

1. Use a suitable hand operated pump device to drain the fuel through the filler tube into an approved container.

Before disconnecting any fuel lines from the fuel tank, thoroughly clean around all hose connections.

1. Disconnect the fuel filler vent hose from the fuel tank.
2. Detach the fuel filler hose from the fuel filler inlet tube on the fuel tank. Position the hose out of the way.
3. Disconnect the vapor hose from the front of the fuel tank.
4. Detach the fuel return pipe and position the hose out of the way.
5. Disconnect the two rear rubber exhaust hangers from the rear of the exhaust system and allow the exhaust system to hang down slightly.
6. Unfasten the exhaust shield mounting bolts, then remove the exhaust shield.
7. Support the fuel tank with a suitable jack.
8. Remove the two bolts securing the fuel tank straps, then swing the straps out of the way.
9. Lower the fuel tank enough to disconnect the vapor hose from the fuel sender assembly and the vapor hose from the vapor pipe at the rear of the fuel tank.
10. Detach the electrical connector from the fuel sender assembly and remove the two retaining clips.
11. Remove the tank from the vehicle, slowly to ensure all connections and hoses have been disconnected.

To install:

1. Clean all parts well. Inspect the tank for dents, rust or other damage. On high-mileage vehicles, it may be good practice to remove the fuel pump module and replace the flexible strainer on the fuel pump.
2. Position the fuel tank under the vehicle and raise the tank with a suitable jack.
3. Connect the vapor hose to the fuel tank at the vapor pipe at the rear of the tank and connect the vapor hose to the sender assembly.
4. Attach the electrical connector to the fuel sender assembly.
5. Connect the fuel feed and return lines to the sender assembly.
6. Raise the tank into position into the vehicle and swing the mounting straps under the tank.
7. Install the front fuel tank strap mounting bolts and tighten to 35 ft. lbs. (47 Nm).
8. Remove the jack.
9. Connect the fuel return pipe to the fuel feed pipe.
10. Attach the rear fuel feed pipe to the inlet side of the fuel filter.
11. Tighten the line fittings to 16 ft. lbs. (22 Nm). Make sure to use a back-up wrench to prevent the fuel filter from turning.
12. Connect the vapor hose to the vapor pipe at the front of the vehicle.
13. Attach the fuel filler vent hose to the tank. Connect the fuel filler hose to the fuel filler neck of the tank.
14. Install the exhaust heat shield and the mounting bolts.
15. Position the exhaust system and install the rubber hangers.
16. Carefully lower the vehicle, then refill the fuel system
17. Connect the negative battery cable, then install the fuel filler cap, if not done already.
18. Turn the ignition switchONfor 2 seconds, OFF for 10 seconds, thenONand check for fuel leaks.