Put new gas cap on check engine light still on
Could be a small hole in your filler tube, or the vent tube that runs beside the filler tube. Its no big deal as long as its not leaking gas. Do you see spots under car after fill up? Smell gas after fill up? When you take gas cap off to fill, do you hear air being sucked in or
vented out?
There are several "codes" related to Gas Cap, so it could be something different. First, it may take some time for the code to clear. Second, I have found that the filler tube sometimes rusts, and this causes enough air leak to cause a gas cap code. Finally, anything in the EVAP system that is leaking could cause a code. There is an EVAP solenoid that will go bad and this causes a code to be indicated. Not an expensive part, so you may want to look there.
Could be your oxygen sensor or catalytic converter.. You may check for leaks in manifold as well.Mass air sensor could also be at fault.
SOURCE: 2001 cadillac sts, check gas cap, but already replaced it.
you need to reset the codes... unhook the battery for about ten minutes... make sure you have the code for the radio (if required)
SOURCE: My 2002 Cadillac Service Engine Light came on,
the code for gas cap? is also a code for small leak in evap system which includes the fuel /vent lines and canister check that the lines weren't damaged when cat was put in also check coolant sensor in reservoir connections runs by exhaust system
SOURCE: 2002 deville has new evap
Hi,
P0440 - Evaporative Emission (EVAP) System leak.
Charcoal canister is loaded with fuel or moisture
Fuel filler cap is loose, cross-threaded, damaged or wrong part
Fuel tank, fuel filler neck or fuel sending unit 'O' ring is leaking
Fuel tank pressure sensor is damaged, disconnected or it failed
Fuel tank vapor line(s) is clogged, damaged or disconnected
Purge valve vapor line is clogged, damaged, or disconnected
Purge or vent solenoid power circuit is open (check the fuse)
PCM has failed .
As you have checked the cap and canister,you have a leak in in the system, what that is can require extensive testing with a Evap system testing smoke generator
The evaporative emission (EVAP) system is checked by applying vacuum to the EVAP system and by monitoring for a vacuum decay. The Powertrain Control Module (PCM) monitors the vacuum level through the fuel tank pressure sensor signal. At an appropriate time, the EVAP canister purge valve and the EVAP vent solenoid are turned ON, allowing the engine to draw a small vacuum on the entire evaporative emission system. After the desired vacuum level has been achieved, the EVAP canister purge valve will turn OFF, sealing the system. DTC P0440 will set because the PCM is not detecting the expected vacuum. This can be caused by the following components with the conditions listed below:
The fuel cap for the following conditions:
Missing
Malfunctioning
Incorrect
The fuel tank pressure sensor for the following conditions:
Disconnected
Malfunctioning
The EVAP purge line for the following conditions:
Disconnected
Damaged
Pinched
Blocked
The EVAP vent hose for the following conditions:
Disconnected
Damaged
The fuel tank vapor line for the following conditions:
Disconnected
Damaged
Pinched
Blocked
The EVAP canister purge solenoid valve for the following conditions:
Disconnected
Malfunctioning
The EVAP vent solenoid for the following conditions:
Disconnected
Malfunctioning
An open ignition feed circuit to the following components:
EVAP vent valve
Purge solenoid
A damaged EVAP canister
A leaking fuel sender assembly O-ring
A leak in the following items:
Fuel tank
Fuel filler neck
If you still are having problems i would recommend taking your car to a shop and have them diagnose the problem, the dealer has the tools necessary to diagnose the EVAP system properly and repair your problem.
Note - There are few recalls as well for this problem.For more, you need to check with the local dealer.
Let me know,if needed further assistance.
Hope i helped you.
Thanks for using ' Fixya ' and have a nice day!!
SOURCE: check engine light on 2002
try disconnecting the battery for 2 minutes.....the computer usually resets itself and will usually turn off the "check engine" light
The information below was complied by me, it explains what causes the check engine light to come on and the process of finding the cause.
When the Check Engine light (or Service Engine Soon) is turned on, the systems computer control unit (called the PCM) has sensed a fault in the electronic controls of the engine and/or the emission system. When this happens you will seldom feel the car engine run any different. There are about 200 possible system faults (the gas cap is just one of them) that turn the Check Engine light on, to know what has developed a problem you must have the system tested, this is called an OBD2 fault code test, Kragen/Oriley and Autozone parts stores (USA only) do this testing for free.
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