5.3 having some EVAP issues among some others.

[Riordan]

I have a 2009 Yukon 5.3 fuel flex.
I had it taken to a shop because of a code for small evap leak upon taking it to the shop they used a smoke tester on it and were unable to find anything, I have replaced the purge valve by the intake, I have checked my gas cap as well. I'm trying to find a solution for my problem. The truck runs a little rough at idle and I'll notice that my RPMs are jumpy while decelerating, I also have issues with acceleration and hesitation along with hard starting. The truck is pretty much stock the only thing that I have done is had a flowmaster kit put on it, but it did not start doing this until recently. If any information is needed I can post it here. Code is P0442

 

[George B]

What id the DTC code for your evap issue?

 

[Riordan]

What id the DTC code for your evap issue?

P0442

 

[George B]

Might be some help here.

 

[Riordan]

Might be some help here.

the shop that I have taken it to multiple times have told me that they have used the smoke tester on it more than once I have not been able to find anything

 

[Fless]

Smoke test isn't going to show internal leaks; more extensive testing needs to be done. Watch this guy and see what you think about what he says. I'm not saying that this is the solution because we have no idea what tests other than a smoke test were done, if any. Tests with a bidirectional scan tool would narrow it down much closer to the actual cause.

https://www.engine-codes.com/p0442_chevrolet.html

 

[Dave S]

I have a 2009 Yukon 5.3 fuel flex.
I had it taken to a shop because of a code for small evap leak upon taking it to the shop they used a smoke tester on it and were unable to find anything, I have replaced the purge valve by the intake, I have checked my gas cap as well. I'm trying to find a solution for my problem. The truck runs a little rough at idle and I'll notice that my RPMs are jumpy while decelerating, I also have issues with acceleration and hesitation along with hard starting. The truck is pretty much stock the only thing that I have done is had a flowmaster kit put on it, but it did not start doing this until recently. If any information is needed I can post it here. Code is P0442

Assuming you have ruled out the gas cap it’s most likely your purge valve or your vent valve. The purge valve is on the passenger side of your intake manifold (AC Delco 214-1865) $22 on Amazon. I replaced that one still got the code after clearing it. It will probably take a few days to pop back up. Changing the vent valve fixed the issue for me. (23481275) $36 on Amazon. You will need the wiring harness if you don’t want to splice wires. (12957603) $18.50 on Amazon. Genuine GM parts. You will have to drop the spare tire to get to it. They updated the part so it will look different. It just routes differently. Fit perfectly and it is simple to install.

 

[wsteele]

A long time ago I got a P0449 and P0455. The Evap Vent Solenoid valve was bad. I replaced it and that fixed it.

Yesterday I got a P0442. Luckily it was just a loose gas cap. Tightened it and reset the codes, so far so good.

 

[Riordan]

Assuming you have ruled out the gas cap it’s most likely your purge valve or your vent valve. The purge valve is on the passenger side of your intake manifold (AC Delco 214-1865) $22 on Amazon. I replaced that one still got the code after clearing it. It will probably take a few days to pop back up. Changing the vent valve fixed the issue for me. (23481275) $36 on Amazon. You will need the wiring harness if you don’t want to splice wires. (12957603) $18.50 on Amazon. Genuine GM parts. You will have to drop the spare tire to get to it. They updated the part so it will look different. It just routes differently. Fit perfectly and it is simple to install.

I just climbed under the vehicle to inspect the vent valve and it looks like it has already been replaced with a new one because I can see the brand new hose that goes up by the gas cap already attached and the old one is hanging down. I also replaced the valve right by the intake and it looked like it had been replaced not too long before I bought it and still no change.

 

[George B]

Don’t overlook the tank sensor. I had a bad one that didn’t read correctly. Seems there was a video on this by “south main auto”.