I need some help with step by step instructions or video on replacing the purge value on my Yukon. All the videos that I can find are for the wrong 6.2L engine. I have a L86 engine with the alternator on the passenger side. Error code p0442 keeps tripping the computer and from what I have read this is the most common issue with this code. Any help or advice is appreciated. Thanks.

That code is for a leak in the system. Did anyone fill the tank without turning the ignition off? Several things can cause that code. Purge valve is a possible. It has a line coming from the back of the vehicle and another going into the intake. You should test the valve before condemning it.

We have filled the tank with the ignition on with no problems. Even with the gas cap off, with truck running, it does not trip the code. It happens at just random times.

You may have to have it fail the monitor a couple times before it turns on the light.

I agree with carfixer007 above, you shouldn't condemn it before knowing for sure. At the same time, these go out enough that it might be worth ~$20.00 to just swap the part as a test and possible fix. I pulled up a stock photo of the L86 and zoomed in. This looks like your purge valve right here:




It looks the same as many purge valves to get out, a squeeze clip on the vapor line, a lift tab on the plug, and a 10mm bolt. A video of replacement on an older L92 6.2 should work for the individual steps, like this one:

You want to apply 12 volts to the valve and make sure it opens and that it also closes correctly. Make sure there'* no charcoal from the canister in the valve. If there is you need to replace the canister and blow out the lines.

Thanks yall for the advice. Hoping to have have some time this weekend to get under the hood and inspect and test the valve out. We just purchased the Yukon and probably have put 300 miles on it and this code has came up twice. IDK if it matters or not, but when we purchased, the dealership filled it up with gas but unsure if they put low grade in it or not. We filled it up with premium the other day and put some good injector/fuel system cleaner in it and it has not tripped the code yet. We are used to driving BMWs and are aware of how bad/low grade gas can influence a vehicle'* performance. I seriously doubt this is the reason for the p0442 code, but knew it needed a good cleaning and premium gas anyways.

I will post an update after I check out the valve and lines.

Here'* a good, unobstructed view without it plugged in.

Do not need to spend the extra money on high test fuel. It'* a waste of money and does ZERO for you except drain your pocketbook faster.

Update... It appeared that the vapor line on the purge valve was not attached correctly so I adjusted the line in hopes that was the problem. It drove for a good 3-4 days without check engine light coming on. Went to crank this morning and the check engine light came on again. It appears that I only have problem when the fuel is at half a tank and under. I will take the valve off this week and inspect/test to see if it holds pressure.