Welcome to the forum
What did the old spark plugs look like?
They are the window to engine operating conditions
Google: spark plug condition pictures
Try this test
turn on key count to 3 then turn off key
Repeat that 3 times
Then try to start engine
If it starts right up and doesn't misfire then your Check Valve in the fuel pump is bad, you are losing all the fuel pressure when engine is off.
All cold engines need more gasoline to run, that is what the Choke Plate did on a carb.
Fuel injection can't use a Choke Plate, no Jets, so computer must "know" engine is cold, and then bump up the fuel mix to Rich so engine will run correctly when cold.
Computer uses the ECT(engine coolant temp) sensor to learn engine temp.
This is not the same device that is used for the temp gauge, that is a SENDER, not a sensor.
Lets see if ECT sensor is working.
When you turn on the key the computer will open the IAC Valve all the way for starting, hot or cold.
When you start engine cold, do not touch gas pedal, the computer will keep the idle above 1,100, so when engine starts RPMs should go up to 1,500+, IAC Valve is open all the way, then RPMs should drop a little as computer starts to close IAC valve, how far it closes is based on ECT sensor temp, colder temp higher idle.
Then as engine warms up computer will start closing IAC valve bit by bit until engine is at operating temp and "Target" idle is set, 650 on manual trans, 750 on automatic
Does your system work like that?
If not replace ECT sensor, they are not expensive, $6-$8, but make sure it IS the Sensor not the Sender you are replacing
EVAP system codes can take two weeks to go away, they can not be reset like other codes, once you think you fixed it you have to wait.
It will clear faster if you drive with gas gauge between 1/4 and 3/4, so don't fill up, it won't run tests unless gauge is between 1/4 and 3/4.
You can not force a test, and computer takes it's sweet time running the tests, EVAP system must pass test 2 or 3 times before code will clear.
Last edited by RonD; 1 Week Ago at 06:55 PM.