ClubLexus - Lexus Forum Discussion - LS - 1st and 2nd Gen (1990-2000)

NEED HELP Random Unkown Misfire

Saiko — Sat, 16 May 2026 20:12:12 GMT

Hey guys! I recently joined the club with a 1997 LS400 Coach edition, love the machine very much, But I'm suddenly having a pretty serious issue.

I have started to experience a misfire on cylinder 7 at idle, it happened about 2 days after replacing the plugs.

What is stumping me the most is that its sounds like almost a backfire through the exhaust on that cylinder, and I'm ONLY getting a code for that cylinder misfiring.
I pulled the plug back out to look at it and it doesn't have any fouling or strange appearance. I used NGK Laser Iridium plugs. The car also does have a fuel treatment in the tank (LiquiMoly) and a full tank of Premium.
Everything seems to be seated, and the misfire only seems to occur at idle, however I do believe that after 2k rpm the cylinder goes dead as well. Valve Cover gaskets are not leaking as I replaced them 2 weeks ago.

I did notice however that when it was colder this morning there was no misfire, it seems to be following outside temperatures. I drove it on the interstate on a cold morning and had no issues with my entire 3 hour trip (68f outside that day)

What could it be? What should I look at next? I just picked up some coils and will install them tonight.

Timing belt

Randy173737 — Fri, 15 May 2026 19:45:45 GMT

Hello all! About to change my timing belt on the 97 LS400 im going to get aisin one. I was hoping someone got the one off rockauto just to make sure its legit. Secondly any suggestions in things to replace, look out for, and or shortcuts? After im thinking about replacing the intake manifold gaskets also any advice on those? Much love for those who help!

Best,

1995 LS400 - Finally added CarPlay and speakers/sub

Norrov — Fri, 08 May 2026 18:57:56 GMT

Figured I�d make a post since it�s kind of pain in the *** to find information on these cars!

I�ve had this car since 2013 ish and bought it for 2K it�s my daily driver now and just wanted CarPlay, hands free and some decent sound. Decided on the sub on the rear deck instead of box since i commonly fill up the trunk.

it has a salvage title when I bought it but it�s solid mechanically and I keep that way. Looks okay from a hundred feet but definitely has some dents and poor bodywork on the front left fender. Now a mangled front bumper thanks to a coyote that ran out infront of me last year.

equipment list:

Pioneer DMH3050NEX, plus backup camera, headliner mic and dashcam (Deleted factory amp, CD Player and car phone)
Amp - Kicker CXA400.1
Front - Kicker 46CSS654
Rear - Kicker 46CSC654
Sub - Kicker 48CWR82. Made a little cradle out of 3/4 MDF for it and took the router to it to make a shelf for the sub, and I routed the bottom so it would sit flat on the ridges of the rear deck. I put stripes of dyna mat here and there on both sides of the rear deck. Put everything back and it looks factory still. Used the 4 threaded m6 holes to hold down the MDF, the ones that used to hold the original sub down. Also re used that blue connector the original sub used for wiring, and spliced more wire on it to reach the coil in the trunk.
Didn�t get pics of the doors, wasn�t too bad once I found all the hidden places Lexus puts screws. I�ll take of pics of where they are, it�s not bad once you figure out where they�re all hiding.

Definitely a huge improvement and makes the car feel like new! It�s my first audio install I�ve done aside from just throwing a head unit and using the adapter harnesses in a few Ram pickups.

I just ran a new 8 wire 16awg cable plus another 4 wire for the remote wire for the amp and some 12V power for adding in some rear USBs from the head unit to the passenger seat.

Put the kicker amp under the passenger seat where the factory one was and routed an 8awg from there to the battery, there�s a easy spot through the firewall under the glovebox, you got to remove the glovebox assembly to get to it. I just grounded it to the body of the car at the bolt that was holding the old amp bracket up.

the backup camera and sub you had to remove the back seats, C-Pillar and rear deck shelf. I used the drivers side cable runway to the trunk for the camera wire, to wire the camera I just cut the red/white wire for the reverse lights near the parking brake under the trim and used that to power the camera and flip the HMI on the head unit.
I did remove the A pillar on the passenger side to hide the wires for the mic and the dash cam in that and the headliner.

My car had the original pioneer system, factory amp under the passenger seat, not the Nak system
which is different color scheme and system entirely, think the amp and stuff for that system is in the trunk.

Sub
green/black +
pink/black -
Drivers side Front speakers Front Left
Pink + Purple -

Front Right
Light Green + Blue -

Rear Left
Black + Yellow -

Rear Right
Red + White -
I cut them off the harnesses and just spliced them, left enough on the harness so you could re use it.

used fuse taps from the inside fuse box location and the hood fuse box for 12V and ACC on the radio.

I hid the GPS helper under the shifter trim, and ran a usb for the CarPlay under that into the center console where the phone used to be (I removed it and the CD player for more room)

LS400 intake air hose help

Smith01 — Thu, 07 May 2026 19:32:56 GMT

Hey all I�m looking for a new intake hose for my LS400 1996. It�s the one right after the MAF sensor. 17881-50050 Part number. Unfortunately it�s discontinued literally everywhere. Mine is super split and cracked and I want to replace it. Are there any good aftermarket options or would a 94 hose fit? They look similar. All the aftermarket hoses I found wouldn�t be long enough. What does everyone else do? Considering this hose is 30 years old I�m sure lots of other people have encountered the same dilemma.

Replacing starter contacts, what should I do while I have the manifold off?

Frey199 — Tue, 05 May 2026 23:05:30 GMT

Going to be replacing my starter contacts soon on my 98 and i'm just wondering if there is anything I should do while i'm in there? Going to be replacing the lower manifold gaskets as well as the bypass gaskets, but other than that I cant think of anything. Also, are there any tips for getting easier access to the starter bolts? Any help is appreciated!

1997 LS400 transmission leak

89SSC — Tue, 05 May 2026 17:54:40 GMT

Good afternoon,
I have a 1997 LS400 that I am replacing the engine and transmission in , with lower mileage units. I have a leak coming from a sensor on the drivers side rear of the trans. Mounted just above the oil pan.It is the white sensor plug just to the left of the transmission mount. This photo is not mine, it is for reference only.
Could someone please tell me what sensor this is , so I can order the correct seal / o-ring? Thank you for your assistance!!

95 LS seat will not slide forward or backward

blkstealthpaid4 — Mon, 04 May 2026 01:26:06 GMT

This is for both seats doing this.it reclines fine but both sliders do not work on both seats.Chatgpt said the track or obstruction.Any experience with this?

Need rear hub for 1990 celsior

Bmeans94 — Fri, 01 May 2026 23:29:56 GMT

I seriously cannot find anything online. I just bought the car a couple months ago and the tires dry rotted out so I swapped them. Dude at the tire shop said i need rear hubs bad.. However on the list or things wrong with the car I remember one or the things just said rear bearings. I can find the bearings easy. Would I be okay just swapping out the bearings for now until I find the hubs?

Head Unit Capacitor Question

as99east — Tue, 28 Apr 2026 13:29:12 GMT

Sorry if a silly question. For this large capacitor in my stock 95 Pioneer head unit, is this leaking or some kind of factory applied adhesive? It doesn�t look like leaking based on other leaking capacitors I�ve replaced but wanted a second opinion I guess.

Second question would be, if I am going to solder in an aux cable, should I replace this larger capacitor preventatively if this isn�t a leak or if no symptoms leave it alone?

1993 LS400 MAF Sensor

dplumley5 — Sun, 26 Apr 2026 04:27:08 GMT

Today I was an idiot. My LS400 has had an issue recently where it will hesitate a bit from a stop, and while cruising at maybe 10-15% throttle it would buck a little bit. I already replaced the TPS and adjusted it, so I suspected maybe it was the MAF. I didn't realize these cars used a rare karman vortex maf, and I cleaned the thing with CRC MAF cleaner....bad move. It made my problem much worse. I realize now that I probably destroyed my sensor after using the CRC cleaner. So I have been on the hunt for a new MAF all day today, and have found that a used OEM sensor is just about my only option. Obviously the cheap chinese replicas likely won't work. I am baffled that there isn't much aftermarket support with these sensors, and that OEM is pretty much the only option. So, I was curious...is there any way to get rid of this vortex sensor entirely and convert to a typical hot wire maf? Does anyone have experience with this? Is it even possible while keeping the stock ECU? I'd like to do a standalone ecu one day, but that's a whole lot of work and probably isn't possible without swapping in a manual transmission.

Need help - what transmission to pair with 1993 motor/ecu?

Sheepymanman — Fri, 24 Apr 2026 23:10:40 GMT

Hello,

Been researching a build for a 1uzfe I'm receiving from a 1993 LS400. Put simply there's just so much contradicting information on various forums/wikis/catalogs, and I just want a concrete answer. I apologize if this is a stupid or FAQ but I just want to ask for myself and get a current answer from someone much more knowledgeable than me, before I commit hundreds or thousands of dollars towards parts.

A340E (30-40LE) or A341E (30-41LE) to go with a 1993 model year LS400 1uzfe with OE ECU and wiring? Which was OEM? Are they bolt-on interchangeable/with what modifications are they interchangeable?

Thank you,
Sheepy