Fuel Cap tighten message

[swathdiver]

Gotcha, I don't have a scan tool though...

Heading down the east coast of Florida anytime?

 

[latvius]

Unfortunately no, wonder if I should take it to a shop?

 

[swathdiver]

Unfortunately no, wonder if I should take it to a shop?

If you don't see anything obvious when you check the wiring then consider purchasing a decent scan tool that can read ABS codes. They have these little OBDII adapters that hook up to your phone via an app. Not quite Tech2 but might be enough to help. @randeez Randy here and some of the guys have these, let's see what they say about the capabilities of those things first.

 

[latvius]

I have one of those, I use torque app and have http://www.obdlink.com/lxbt/ the older version so I can erase the codes and scan them but it wont let me actuate anything advanced like that.

 

[KATfishing]

I had a similar problem... I replaced purge valve, vent valve/assembly and fuel cap, but each time I cleared the related code a new and different code would soon come up and became less specific (i.e. small leak, large leak, etc.). I took it into my local shop and they discovered a leaky fuel pump assembly... gasket was no longer sealing properly. New fuel pump kit made all the codes disappear. The codes point you in a direction, but the issue can be somewhere else in the system.

 

[latvius]

Interesting, I recently changed out the fuel pump because the fuel would bleed back down, bad check valve I believe. It came with a new o ring which I used but maybe a place to check.

 

[ssrobzoom]

The Evap test port has the green cap on it. Looks like a little green valve cap. It’ll be on the Black Evap line that runs to the purge valve that is on the intake manifold.

The vent valve has to be commanded closed with a scan tool. It’s the Evap vent valve solenoid I believe is gm’s name for it.

I'm fixing to replace my with AC Delco #214-1005 which does not have the test valve port. Because I'm getting the Gas Cap message also. The original one does should I get the one that does have it?? if so what the part number needed?? I have a 2005 Yukon SWB 5.3 non flex 2WD.