I was pumping gas and car stops running and didn't want to start check engine light is on i took to auto zone got code p0451 what's going on 2011 lacrosse

SOURCE: Codes P0303, P0451,P0440- gas cap replaced 2X check engine light

PO303 # 3 cylinder miss fire: check ign coil and wires,
PO451
PO440: looks like perhaps something to do with the fuel line change! i would look further into it before traveling far perhaps a really well reputed garage can help?????

SOURCE: check engine light on;engine codes p0420 and p0773

I looked up the codes you posted.
P0420 is showing a bad oxygen sensor on bank #1, the one down by the catalytic converter.
P0773 is an electrical problem with the shift solenoid E.
A bad oxygen sensor would cause lower fuel milage.

SOURCE: Check engine light is on...

I am not going to lie, I came across this in another forum a while back and I would love to retype it and interpret it here but it is too much. I looked at it and verified that the information here is information that could be found through my scan tools so here it is!

P0440
The fuel tank pressure is atmospheric pressure after the vehicle is driven for 20 min (2 trip detection logic).

Possible Problems
Fuel tank cap incorrectly installed <= Most common
Fuel tank cap cracked or damaged (Toyota part only)
Bad vapor pressure sensor/circuit
Vacuum hose cracked, holed, blocked, damaged or disconnected 
Hose or tube cracked, holed, damaged, or loose
Fuel tank/filler neck cracked, holed, or damaged
Charcoal canister cracked, holed, or damaged (collision)

In above description, check hoses between vapor pressur sensor and VSV for vapor pressure sensor and charcoal canister. Also, hose between charcoal canister and fuel tank.

SOURCE: i have 2000 chevy impala 3.4 engine i have check

This indicates a fuel vapor leak in the EVAP control system. It means a very small leak has been detected. In fact, the leak can be from a hole as small as 0.04" in diameter. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine.
code P0442 most likely means one or more of the following has happened:

• A loose or improperly affixed gas cap
• A non-conforming gas cap (i.e. not factory/original brand)
• A small leak/hole in a fuel vapor hose/tube
• Other small leak in EVAP system
• Faulty vent o-ring seal

• Remove and reinstall the gas cap, clear the codes, and drive for a day and see if the codes come back.
• Otherwise, replace the gas cap, or
• Inspect the EVAP system for cuts/holes in tubes/hoses

Michael Thomas

• 3056 Answers
• Posted on Dec 27, 2010

SOURCE: Check engine light is on took to auto zone they

Hello there:
P1167 and P1166 codes relate to the primary O2 sensor heater malfunction.
there are two different O2 sensors, a "universal" sensor from Autozone and a supposedly OEM sensor from O'Reilly's. Both of them may cause the car to throw a p1166 or P1167 code and run rough. so i highly recommend getting a O2 sensor from Honda, and this will fix the problem .
It turns out that none of the aftermarket probes from Bosch or Denso will work on a ULEV (F23A4) 4 cyl. engine. Honda had different part number probes for the normal VTEC 4 cyl. and the ULEV Vtec engine and the probes look different and have different length cables. The computers at O'Reilly's, Autozone, or NAPA made no distinction between these two engine types.