Check engine light

[Littrelldl]

I have a 2002 with a 4.0 automatic 4x4. I have been trying to get the engine light and the gas cap light to go off for years and have taken it to two different shops with no luck!! What now?

 

[adsm08]

I have a 2002 with a 4.0 automatic 4x4. I have been trying to get the engine light and the gas cap light to go off for years and have taken it to two different shops with no luck!! What now?

Step 1: Find evap issue.
Step 2: Fix evap issue.
Step 3: Clear codes
Step 5: Profit.

 

[RonD]

I have a 2002 with a 4.0 automatic 4x4. I have been trying to get the engine light and the gas cap light to go off for years and have taken it to two different shops with no luck!! What now?

Welcome to TRS

You need to start your own thread
Include the code or codes if there is more than one

Were these Auto shops you took the truck to?
I can't see an auto shop not fixing an EVAP code, just not that complicated of a system, and ALL vehicles have to have an EVAP system, not a Ford or Ranger specific thing, just general automotive repair

 

[Littrelldl]

Welcome to TRS

You need to start your own thread
Include the code or codes if there is more than one

Were these Auto shops you took the truck to?
I can't see an auto shop not fixing an EVAP code, just not that complicated of a system, and ALL vehicles have to have an EVAP system, not a Ford or Ranger specific thing, just general automotive repair

The first two were Ford dealership service centers and the third was an independent shop!

 

[Littrelldl]

RonD, I have taken my truck to two dealership service centers and one independent shop with no one seemingly able to find the problem!! The codes that come up are P0455 and P0457

 

[adsm08]

P0455: Gross leak/no flow
P0457: Leak/fuel cap loose

The evap system only uses a single sensor, so it has a hard time telling the difference between a system that can't hold any vacuum, and a system that isn't opening to pull itself into a vacuum.

So you could have a large leak, you could have a mechanically stuck valve, or you could have a bad pressure sensor.

The first step would be to check the system and see if it can be pulled into vacuum, even a little bit. This would involve a scan tool to monitor the PIDs and see if the fuel tank pressure drops when the purge valve is commanded to open.

If it can, the next test is to see how long it can hold vacuum by closing all the valves and seeing how long it takes to equalize to atmosphere.

If it equalizes quickly then you hook up a smoke machine and try to find the leak.

If the system is unable to pull into a vacuum, then you would check the valves to see if they are able to open and close properly.

 

[RonD]

Get a helper with good lungs
Get a hose and a damp towel/rag

Take gas cap off
Put hose into filler
Wrap damp towel around hose and hold it in filler to SEAL the gas tank
Blow into the hose, the part where good lungs come in

Listen for where the air is escaping, the codes mean air is escaping
Listen by the gas tank AND in engine bay

DO NOT use an air compressor for this test, lungs can only generate 2 to 3 psi of air pressure so you will not blow off any EVAP fittings
Air compressor WILL BLOW OFF EVAP FITTINGS

If you can blow into gas tank AND it holds pressure, then pressure sensor might be the issue, or its a computer issue
But far more likely you will hear the air escaping and tank won't hold pressure

 

[mikwar50]

I had P0455, thought it was the evap vent solenoid valve. When I went underneath to replace it, I found that some varmint (probably a squirrel from the size of the teeth marks) had chewed a hole in the inlet pipe of the charcoal canister. Fixed it with some emergency repair tape, problem resolved. I went ahead and changed the vent valve anyway. Been running fine for over a year.

 

[Eddo Rogue]

Pull down your pants, run backwards through until you find another truck for sale, any truck, then buy it.