execlex

So let me start off by saying I have searched extensively all around the web with some guesses, but no real clear answer. I have a 98 LS400 and after putting in some gas the yesterday, I drove about 4 miles and got Check Engine light along with VSC off. I searched and found that the gas cap could be the culprit, sure enough - my gas cap was almost falling off. I realized my gas cap is aftermarket and comes loose very easily no matter what. I went to Lexus today and bought a new one for $33 plus tax. So after resetting the ECU by pulling the negative off the battery, I am now feeling slight sputtering while coasting at speed and idling in drive. I went to autozone before all of this and got random misfiring codes as well as VVT-i bank 1 code. Again, sure enough there was a loose connector on the OCV - clicked it in place and Reset the ECU again - this time with new cap on and OCV plug all the way on. Got about 10 miles running good, no sputtering or anything, then right before I get home, CEL & VSC again - and the sputtering at idle and constant speed. I pull in to park and noticed a very strong sulfur smell coming from the exhaust.

I am going to go get the codes pulled again tomorrow, there is an autozone right down the street from me, I'm hoping to see the VVT code gone. Overall I would say I did 40-50 miles with the bad gas cap(about 20 of those with the cap pretty much off, it worked it's way off and came loose very easily), and only about 25 since the new cap, have yet to put new gas in... could the Emission system have air in it causing the sulfur smell and misfiring? I also realized I could have gotten bad gas from a local arco station, now I'm not going anywhere but chevron from now on. the car ran fine before the crappy aftermarket gas cap was loose and filling at arco... and now all these problems seem to be a domino effect of that aftermarket cap/and or gas. Is there a number of miles I should expect to "clear" the evap system or something? should I run it empty and go fill up with good gas from chevron or shell? It seems to accelerate and drive normally, only slightly "lurching/sputtering" (which feels like the misfires) at constant speed or idle., idle is lower than usual, about 400-500 RPM. I am hoping somebody else experienced something similar and can reassure me things will work out.. I am worried and wish I would have replaced the gas cap earlier AND not used shoddy gas. I hope I haven't messed anything up by driving so much with a faulty gas cap. All responses welcome, I am at my wit's end.

PureDrifter

iTrader: (10)

you should have pulled the code from the get-go instead of assuming you knew what it was.

You could have a myriad of things wrong, but im rather confident in saying that a loose/missing gas cap wouldn't cause the issues you're describing (sputtering/misfire).

get the codes read and come back.

execlex

thanks for the reply. I will get the codes first thing tomorrow. I only assumed because the gas cap was aftermarket and kept coming loose and was pretty much off when I checked it. I wouldn't have felt right if I didn't replace it. It now holds snug and I feel better about that, but I'll be back tomorrow!

execlex

Didn't realize my buddy had a reader so I got the codes. here they are.

P1349 "VVT system malfunction (bank1)"

P0300 "random cylinder misfire detected"

P0301 "Cylinder 1 misfire detected"

P0303 "Cylinder 3 misfire detected"

P0305 "Cylinder 5 misfire detected"

P0307 "Cylinder 7 misfire detected"

So, VVT bank 1 and random misfires which apparently is the same side as cylinders 1,3,5,7. so, is my Oil
Control Valve the culprit? if so, do you know the part #?

execlex

I think I found the part number .. 15340-0F010 ? I will wait for your feedback before moving forward with anything.

PureDrifter

iTrader: (10)

look in the UCF2x faq, there's a link to a tutorial for the vvti OCV.

sounds like you unplugged the cam sensor or some part of the harness on bank1. (bank 1 has cylinders 1,3,5, & 7.) go inspect the area, if there's any oil on the plugs get some CRC electrical contact cleaner for them.

execlex

hmm.. couldn't find it under the stickied faq written by you, I might be looking in the wrong place. I really can't find anything specific to the LS400, I found this for the GS300, will the same steps apply? sorry, I feel bad for asking so many questions.

https://www.clublexus.com/forums/per...-filter-3.html

execlex

yeah, there's nothing related to the VVT-i in the UCF2X FAQ... but atleast I found the issue. If I can't get it working after cleaning, I'm just buying a controller and filter. Thanks for the help. I just find it odd that it took my fuel cap off to get my OCV to malfunction, or atleast throw up my CEL & VSC. I did nothing in the engine bay that would have caused me to remove a plug, if anything I made a connector click for better contact after the fact... and since it ran for about 15 mins with no issues and then saw the issue after engine warming up, somebody else on here had experienced the same issue with their OCV sticking after operating temperatures were achieved. I will post an update to help others in the future who might experience this issue. Thanks again puredrifter

RA40

iTrader: (6)

That was quite an ordeal tracking that problem down in the 2GS section. Keep us posted.

LScowboyLS

this is what sounds likely to me