P0442 Frustrations

[Jeepoftheseus]

Hey everybody, weeks after my first post I'm still chasing this evap leak. I'm looking for some perspective and recommendations about what to do next. Here's the story so far:

A little while after I bought the jeep it threw code P0442. I read around the forums and it seemed pretty clear that I should just immediately smoke test the jeep rather than throw parts at it. I studied up, drew a diagram of the evap system, smoked it, and checked everywhere except the top of the gas tank and the filler neck. (The reason I didn't check there is because I plan on rebuilding the fuel pump assembly, but the denso pump itself had a crazy 6-8 week wait time, so I'm still waiting for it to come. I don't want to drop the tank till I can do that job too).

Me and two buddies armed with flashlights and lasers couldn't find smoke anywhere. We spent a good hour looking at it. There's a new gas cap on the jeep, so I suspect the PO was chasing the same issue before they sold. In the process I pulled the CPV and the LDP, inspected them, then reconnected them. When we threw in the towel I turned the jeep back on and was surprised to find the CEL had gone away.

A few weeks later the CEL came back on. Recently, I installed the big 7 jeep cables and in the process had the battery disconnected. While doing the job I cracked the vacuum line from the LDP to the manifold and replaced it. When I turned the jeep back on, naturally, the code was gone. After a day or two I went to have the emissions done but they said it wasn't emissions ready.

So I've been driving the jeep around the last week or so (just quick errands) hoping the engine would duty cycle and no CEL has come back.

So I drove over to Autozone today and asked them to check if the jeep is emissions ready (because my $70 live scanner for some reason can't do this on my 98').

Annnnd they told me that it's showing a P0442 code and is not emissions ready, even though the CEL isn't on. What do I do from here?

 

[Chris]

So the code is a pending code? Have you tried clearing the pending code to see if it comes back?

 

[Jeepoftheseus]

That was helpful. Truthfully I didn't even know pending codes were a thing until I read your comment and looked into it. So it seems like I'm in a position where I have to wait for the evap duty cycle either to identify another p0442 or detect no leaks and clear the pending code. If I clear the code on my own I wont be able to pass emissions

So to collect my thoughts here, it must be that the leak is so small smoke cant really be detected, or its coming from the fuel tank somewhere-- which I haven't gotten my eyes on yet . I suppose another possibility is that the fuel cap is bad, but it looks basically brand new so I don't think that's the case.

 

[C.J. Roberts]

I had a similar problem when I got the Muddog 10 years, (REALLY?!) ago. My mechanic chased it on and off for two years. We changed out just about every component, line, and fitting there is. Even the gas tank!
He finally figured out that the Schrader Valve on the test port was leaking. He removed it and replaced it with a piece of tubing, and I've been leak free ever since.

 

[Jeepoftheseus]

I had a similar problem when I got the Muddog 10 years, (REALLY?!) ago. My mechanic chased it on and off for two years. We changed out just about every component, line, and fitting there is. Even the gas tank!
He finally figured out that the Schrader Valve on the test port was leaking. He removed it and replaced it with a piece of tubing, and I've been leak free ever since.

This is helpful and very easy to test. Gives me another reason to buy that vacuum parts kit I've been eyeing on Amazon.

 

[Jeepoftheseus]

Update:

I passed emissions today. I went back and took another look at the vacuum lines running from the Schroeder valve as suggested by @C.J. Roberts . In the process of trying to get it off, I accidently busted a couple of the hard plastic lines, which had become very brittle. This led me to take a closer look at all the hoses. As i squeezed them and looked down the tube, I noticed that the hoses were in fact splitting a little at the outlet. I had not noticed before because when I inspected them I didn't give them a squeeze. I replaced all of these with new tubes from my local AutoZone. none of it looks particularly good, but my scan tool told me today that the jeep had run the evap duty cycle and not detected any codes. Only one test was incomplete, the one for the cat, but Arizona will pass you with an incomplete test as long as it isn't the evap duty cycle. Having passed emissions, I was finally able to register the jeep under my name and get a new title. I'm mighty pleased and deeply appreciative of everyone on here and my other post who helped me think through the problem. I'm a big fan of the forum. Registered just in time to take her on a beginner wheeling trip to the Mogollon rim this easter weekend!

 

[lBasket]

Update:

I passed emissions today. I went back and took another look at the vacuum lines running from the Schroeder valve as suggested by @C.J. Roberts . In the process of trying to get it off, I accidently busted a couple of the hard plastic lines, which had become very brittle. This led me to take a closer look at all the hoses. As i squeezed them and looked down the tube, I noticed that the hoses were in fact splitting a little at the outlet. I had not noticed before because when I inspected them I didn't give them a squeeze. I replaced all of these with new tubes from my local AutoZone. none of it looks particularly good, but my scan tool told me today that the jeep had run the evap duty cycle and not detected any codes. Only one test was incomplete, the one for the cat, but Arizona will pass you with an incomplete test as long as it isn't the evap duty cycle. Having passed emissions, I was finally able to register the jeep under my name and get a new title. I'm mighty pleased and deeply appreciative of everyone on here and my other post who helped me think through the problem. I'm a big fan of the forum. Registered just in time to take her on a beginner wheeling trip to the Mogollon rim this easter weekend!

This shit grinds my gears about emissions. Not being able to register it because you can't pass, sure. But needing to pass to get the title in your name is BS. It shouldn't be involved in ownership documents.

 

[Jeepoftheseus]

This shit grinds my gears about emissions. Not being able to register it because you can't pass, sure. But needing to pass to get the title in your name is BS. It shouldn't be involved in ownership documents.

I agree. The whole situation was super sketchy. The dude who sold it to me swore up and down it was smogged and there were no issues. Then when we arrived at the MVD it turns out it hadn't passed emissions in two years. I immediately knew the jerk totally just cleared the code and tried to play it off. Total idiot. I almost backed out of the deal but the price was still good and I knew it wasn't going to be expensive to fix, just time consuming. When the CEL came back on a week later I knew I had guessed correctly that he had just cleared the code. I should have been able to register it right then and there and get a title while he was still in the room.

 

[Moglocker]

I agree. The whole situation was super sketchy. The dude who sold it to me swore up and down it was smogged and there were no issues. Then when we arrived at the MVD it turns out it hadn't passed emissions in two years. I immediately knew the jerk totally just cleared the code and tried to play it off. Total idiot. I almost backed out of the deal but the price was still good and I knew it wasn't going to be expensive to fix, just time consuming. When the CEL came back on a week later I knew I had guessed correctly that he had just cleared the code. I should have been able to register it right then and there and get a title while he was still in the room.

You couldn’t just get title only?I’ve had to do this on project cars that will be a while to get roadworthy.

 

[Jeepoftheseus]

Update:

After a weekend wheeling, my small evap leak has become a P0455 large evap leak! On the bright side, at least the thing is registered now so I have plenty of time to fix it. In addition, hopefully smoke testing it will actually work seeing that the leak is larger now. I'm starting to suspect that all my messing around with vacuum lines under the hood may never really have been the problem, I suppose it's also possible the large leak is unrelated. I'll keep updating the post as I search for the solution.

 

[TN_Project_Jeep]

Update:

After a weekend wheeling, my small evap leak has become a P0455 large evap leak! On the bright side, at least the thing is registered now so I have plenty of time to fix it. In addition, hopefully smoke testing it will actually work seeing that the leak is larger now. I'm starting to suspect that all my messing around with vacuum lines under the hood may never really have been the problem, I suppose it's also possible the large leak is unrelated. I'll keep updating the post as I search for the solution.

Any updates on your large leak?

 

[Jeepoftheseus]

I haven't smoked it yet because it's pretty hot out I'm Arizona now. The smell of gas in the cabin is so strong though that it's basically un-drivable. I'm hoping that means the smoke will quickly ID the leak.

 

[Moglocker]

I haven't smoked it yet because it's pretty hot out I'm Arizona now. The smell of gas in the cabin is so strong though that it's basically un-drivable. I'm hoping that means the smoke will quickly ID the leak.

If you have recently installed a fuel pump ,probably didn’t get the ring tight enough (like me)make sure you grease the threads.but it is probably tank related.