Check Engine Light...need help!!

Check engines lights on with several codes all evap codes! I work on diesels, all has to be the same concept right?
1. Evaporative Emission Control System Incorrect Purge Flow
2. Evaporative Emission Control System Leak Detected (small leak)
3. Evaporative Emission Control System Vent Control Circuit Malfunction
Have changed the fuel cap and didnt help, started with the same stuff gonna try all new hoses next but hoping someone could give me a better direction!!
Thanks!

 

Fuel cap code will take a number of cold restart cycles to clear.

Yes, the canister may be shot... when refueling, do you "top off" the tank?
If so, it's time to stop doing that.

 

thats bad?

 

Topping off can overflow fuel into the evap system.
Once it floods the charcoal canister, it can't properly purge when the valve opens, and you get to buy a new one.

 

Damn!!!! lol yeah i have done it and def knew i shouldnt!! i go on long trips sometimes and try to get what i can in there! I was affraid of that havn't found one cheaper then 300!! and it dont look fun to change!

 

Sounds like your vsv has crapped.
It comes with the canister assembly.
If you had access to the proper scan tool a active test on the valve would conform it being stuck.
Just changed one yesterday. Not the easiest thing to do.
You should really get the switching valves checked.
#1 and #3 send me in that direction .
#2 could be a result.
If you do find it was the canister ass. Make sure you clean the filler neck seal area where your cap rides. Rust or from tapping the nozzle in that area can damage the tube and make an improper seal.
Good luck.

 

The extra half gallon that you might get in by topping off is only going to add another 10 miles... and that's assuming that you aren't actually only adding a quart with another quart dumping into the evap system... which is just flushed into the intake via the purge valve when the engine is running a high vacuum.

I know you have a 1st gen with a smaller tank, but 15, 17, or 21 gallon tank, what you can "stuff" into the neck is not going to make a difference in running out. The low fuel light comes on, you still have at least 40 miles left, most likely more.

 

Well i have a scan tool and erased them but all 3 come back everytime!!

 

$300 bucks is the cheapest one ive found jud=st didnt want to throw it at it, but ill take ur advice and "invest" in getting one!! How bad would this hurt my fuel milage?

 

Give the complete system a check from end to end before replacing parts.
Not likely, but on an 04 it could be a frayed hose or connection.
The system is detecting a leak.

 

Yeah true not worried bout running out, i drive 60 miles a day so i feel up every 3 to 4 days and i hate pumping gas.. but like u said stop the stupid crap for a quart of fuel!! thanks again!!

 

Did u pull the bed? i thought bout jus replace every hose on it jus to be safe and go from there! any hoses on it with a press fitting or jus plain hose with clamps?

 

Not sure what your '04 has for hoses and connections.

 

Like i said get the vsv checked before you buy. No need to "INVEST" before the problem is confirmed. A 300 dollar "throw" is not something i would do to a customer and i don't want you to do it either.

 

Ok will do first thing in am! I have a matco scan tool will have to brush up on the skills to use it !!