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Hey CL members, i purchased a '03 UL ls430 recently, gotta say i love the car already, but when i was driving recently, the CEL, VSC off, and the check VSC warning appear one day out of the blue, so i hooked up one of those handheld scanners, and pulled the codes, P0441 (evap system incorrect purge flow), P0442 (evap system leak detected -small leak-), and P0446 (evap system vent control circuit). Do any of you guys have any insight to this problem, there arent any driving issues.
Hey CL members, i purchased a '03 UL ls430 recently, gotta say i love the car already, but when i was driving recently, the CEL, VSC off, and the check VSC warning appear one day out of the blue, so i hooked up one of those handheld scanners, and pulled the codes, P0441 (evap system incorrect purge flow), P0442 (evap system leak detected -small leak-), and P0446 (evap system vent control circuit). Do any of you guys have any insight to this problem, there arent any driving issues.
First thing I would do is buy an OEM gas cap from the Lexus dealer for about $15-$20 to replace the one you have. Do not buy an aftermarket gas cap. It's the cheapest place to start and it fixes those codes more times than not. Besides, If it doesn't fix it you likely need a new one anyway. Another place to look is for a leak in the system. The most common place is under the hood on the drivers side of the motor. Take a 10mm socket, unscrew the two nuts holding the engine cover down. Pop off the cover and look right near the oil fill tube and you'll see some vacuum lines entering a valve looking part and I believe there's a green cap in the location. Some times there is a hose that just falls off and people just slip it back on and its good to go. In my case, the lines where just very loose. Replacing the gas cap and putting hose clamps on those 2 or 3 lines solved my issue which you are having. If your scanner wont clear the lights and codes you can always disconnect the negative battery cable for a while then reconnect. You need to reset all your settings in doing so. I think there may be a fuse you could yank but maybe someone else will chime in on that one. To me its no big deal to reset things if I ever need to.
Initially the code would come and go. Then one day on my way to the airport to pick up my daughter, the VSC lights came on. I researched possible causes while on that short jaunt and stopped at a Lexus dealer on my way home to buy the cap. I did what I described above and its probably been a year and at least 25,000 miles (cant remember exactly) and all is well.
First thing I would do is buy an OEM gas cap from the Lexus dealer for about $15-$20 to replace the one you have. Do not buy an aftermarket gas cap. It's the cheapest place to start and it fixes those codes more times than not. Besides, If it doesn't fix it you likely need a new one anyway. Another place to look is for a leak in the system. The most common place is under the hood on the drivers side of the motor. Take a 10mm socket, unscrew the two nuts holding the engine cover down. Pop off the cover and look right near the oil fill tube and you'll see some vacuum lines entering a valve looking part and I believe there's a green cap in the location. Some times there is a hose that just falls off and people just slip it back on and its good to go. In my case, the lines where just very loose. Replacing the gas cap and putting hose clamps on those 2 or 3 lines solved my issue which you are having. If your scanner wont clear the lights and codes you can always disconnect the negative battery cable for a while then reconnect. You need to reset all your settings in doing so. I think there may be a fuse you could yank but maybe someone else will chime in on that one. To me its no big deal to reset things if I ever need to.
Initially the code would come and go. Then one day on my way to the airport to pick up my daughter, the VSC lights came on. I researched possible causes while on that short jaunt and stopped at a Lexus dealer on my way home to buy the cap. I did what I described above and its probably been a year and at least 25,000 miles (cant remember exactly) and all is well.
Good luck and let us know what you find.
Thanks I will be stopping by to purchase an OEM gas cap tonight, also I will check those vaccum lines as well, thanks for the input!
If it works but comes back in a while. Just erase the code and see how it goes. It may happen a couple of times. I cant explain it other than other people have posted a possible cause is also topping off your fuel past the shut off point and soaking the evap canister? It then may take a few tanks to dry out? It's just something I've read on this forum. I can't verify it but I guess anything is possible. I always round up to the dollar or there about. I've done it for years and I've done it on this car for nearly 100,000 miles. In my instance I highly doubt this was the cause. Mostly because it didn't happen for tens of thousands of miles and hasn't happens for tens of thousands of miles since.
If it works but comes back in a while. Just erase the code and see how it goes. It may happen a couple of times. I cant explain it other than other people have posted a possible cause is also topping off your fuel past the shut off point and soaking the evap canister? It then may take a few tanks to dry out? It's just something I've read on this forum. I can't verify it but I guess anything is possible. I always round up to the dollar or there about. I've done it for years and I've done it on this car for nearly 100,000 miles. In my instance I highly doubt this was the cause. Mostly because it didn't happen for tens of thousands of miles and hasn't happens for tens of thousands of miles since.
Yea I usually dont have to round up to the nearest dollar haha, but i just did a quick check of those vacuum lines you told me about, and they were all tight, except i broke one of the fittings to this mysterious black box, now there will be a definite leak from there, im trying to find a replacement part right now from Lexus.
Quick update, I replaced the part that I broke, apparently it's for fuel vapor or something, I also picked up a brand new OEM gas cap, and I had the codes erased, let's see if the problem comes back.
Are all 3 DTC's back? If so, that's good news because you're dealing with a "Big" leak - those are easier to find. Since you've already replaced your gas cap (and I assume you've checked to make sure the filler neck is not damaged), the next thing to check is the filler pipe leading to the tank.
On the other hand, if only P0442 is back, then you're looking at a small leak which is much more difficult to troubleshoot.
Last edited by rkw77080; Jan 17, 2016 at 02:16 PM.
Are all 3 DTC's back? If so, that's good news because you're dealing with a "Big" leak - those are easier to find. Since you've already replaced your gas cap (and I assume you've checked to make sure the filler neck is not damaged), the next thing to check is the filler pipe leading to the tank.
On the other hand, if only P0442 is back, then you're looking at a small leak which is much more difficult to troubleshoot.
yes all three DTC came back, i will check the filler neck and filler pipe tomorrow!
It's either a leak in the Evap system or possibly the Evap canister. You already replaced one of the possible valves. Take a look at the Evap system component layout and check any of the lines or components.
Error code troubleshooting
