LS 430 Acceleration issues
4th Gear
Joined: Aug 2014
Posts: 4
Likes: 0
From: ca
MAF sensor, or something simple as a bad ignition coil/ coils.
Lead Lap
Joined: May 2006
Posts: 3,682
Likes: 304
My car had the same symptoms in a addition to pinging on hard acceleration. I purchased a OEM Denso MAF from Rock Auto. End of problem. Car rides like a new car. Make sure you disconnect the battery for about 30 minutes before installing the sensor. Good luck.
Advanced
Joined: Jun 2014
Posts: 712
Likes: 237
From: UT
My car idles and runs great and my mpg's are solid, but I have noticed a fair amount of lag if I hit the pedal hard like mentioned in this thread. It can sometimes feel like traction control is trying to engage on dry pavement. That led me to discussion of the TPS, but @bradland discovered 04-06 don't have a TPS.
Maybe I am due to for a TB cleaning?
-I clean the MAF sensor at least twice per year with CFC cleaner.
-I replace the air filter every January no matter what, OEM.
-I use Premium gas always.
-Regularly serviced.
-I had a full transmission flush service 43k miles ago.
-I had the TSB on the transmission programming done about 3 years ago.
-No check engine light. I haven't asked for a code check. Passes emissions with ease.
Another thread mentions "clogged cats". What does that mean?
https://www.clublexus.com/forums/ls-...-no-power.html
This quote intrigues me:
Originally Posted by PNWLS430
This is traction control engaging slightly. It's really weird and scary at times. I've tested the theory by driving without vsc and it never does this. My03
Any further guidance?
Thank you as always!
Maybe I am due to for a TB cleaning?
-I clean the MAF sensor at least twice per year with CFC cleaner.
-I replace the air filter every January no matter what, OEM.
-I use Premium gas always.
-Regularly serviced.
-I had a full transmission flush service 43k miles ago.
-I had the TSB on the transmission programming done about 3 years ago.
-No check engine light. I haven't asked for a code check. Passes emissions with ease.
Another thread mentions "clogged cats". What does that mean?
https://www.clublexus.com/forums/ls-...-no-power.html
This quote intrigues me:
Originally Posted by PNWLS430
This is traction control engaging slightly. It's really weird and scary at times. I've tested the theory by driving without vsc and it never does this. My03
Any further guidance?
Thank you as always!
Last edited by CA2WALS430; Dec 3, 2025 at 09:19 AM.
Racer
Joined: Jan 2004
Posts: 1,923
Likes: 464
From: North Carolina
Clogged cats is the catalytic converter clogged but generally will not be a lag and increase the way it is supposed to be. How much lag time are you talking about. Try battery disconnect to see if that helps and keep transmission in power mode.
Advanced
Joined: Jun 2014
Posts: 712
Likes: 237
From: UT
By battery disconnect, you mean detaching the negative terminal for 30 minutes? I will try, but it only lasts a few months, right? I have also done the 'turn on the car but don't start- accelerator down for 5 seconds-then turn off car and leave key in for 2 minutes' procedure. It helps the downshift thing but it also does not last long.
Honestly, one-one thousand, so probably a full second but when you're getting out in front of a group of cars or out on the highway, that causes nerves.
It's dry here today, I should get out and try power mode and also cancelling the VSC.
Honestly, one-one thousand, so probably a full second but when you're getting out in front of a group of cars or out on the highway, that causes nerves.
It's dry here today, I should get out and try power mode and also cancelling the VSC.
Last edited by CA2WALS430; Dec 4, 2025 at 08:39 AM.
Racer
Joined: Jan 2004
Posts: 1,923
Likes: 464
From: North Carolina
Ok from everything you are saying it is normal for this car because of terrible learning mode and has never been corrected. Remember when I bought car over 20 years ago salesman told me to floor it and still a lag there till catches. There have been times of real scarry moments when I needed it to go but this car does not do it fast enough quickly. My 2020 ES300h UL is instant responsive and feel much safer with that respect. There could have been software update to correct this but no go.
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Advanced
Joined: Jun 2014
Posts: 712
Likes: 237
From: UT
Thanks, Alex. Really interesting perspective as I didn't know you were the original buyer. I tested it a bit today but of course it performed pretty awesome. In a vacant parking lot I was able to get a little lag but not enough to verify VSC or PWR mode. One thing for sure is the VSC certainly contributes to it even if you squeal a little on asphalt, so it certainly is partially the culprit.
Not really a fair comparison I think to your hybrid since most hybrids engage electric until 30 mph and electricity is instant. But just like you said there have been a few freaky moments but super rare since the rest of the time this thing is butter, probably why they were such a hit with the senior crowd.
Oh, and I assume you would tell me the ECM solder fix would not alleviate this issue? I have not had it done.
Not really a fair comparison I think to your hybrid since most hybrids engage electric until 30 mph and electricity is instant. But just like you said there have been a few freaky moments but super rare since the rest of the time this thing is butter, probably why they were such a hit with the senior crowd.
Oh, and I assume you would tell me the ECM solder fix would not alleviate this issue? I have not had it done.
Last edited by CA2WALS430; Dec 4, 2025 at 02:08 PM.
Instructor
Joined: Jan 2018
Posts: 965
Likes: 299
From: WA
CA2WALS430, did you by chance pull off the intake tubing to see the condition of the throttle body? It can get dirty over time notwithstanding all the maintenance and good fuel in your previous post. Look for the tell tale black ring around the throttle plate. If you see that it needs cleaning. It may possibly help your symptom - no guarantee.
Advanced
Joined: Jun 2014
Posts: 712
Likes: 237
From: UT
Thanks, Gents! Alex, yes, that was the answer I predicted. Agreed on the learning mode, BTW. Love this car, but have come to not appreciate that a ton.
Tom, yeah that is a good idea that I kind of buried in my lengthy original post, that maybe it is time for a TB cleaning, though as Alex alludes to above will not likely not resolve. It could help though. @bradland showed me the car care nut video showing how to do it, so now I have to decide how committed I want to get.
Like I said it is not frequent but has created a few freaky moments.
Tom, yeah that is a good idea that I kind of buried in my lengthy original post, that maybe it is time for a TB cleaning, though as Alex alludes to above will not likely not resolve. It could help though. @bradland showed me the car care nut video showing how to do it, so now I have to decide how committed I want to get.
Like I said it is not frequent but has created a few freaky moments.
Last edited by CA2WALS430; Dec 5, 2025 at 07:38 AM.
7th Gear
Joined: Aug 2025
Posts: 7
Likes: 3
My '02 LS had the same exact problem. No codes. I replaced the Mass Air Flow sensor (with an original Denso from Rock Auto) and it fixed the problem. I also cleaned the throttle body. Keep in mind that if you decide to clean yours, do NOT spray cleaner directly into the throttle body. The cleaner can destroy sensitive sensors. Spray some on a rag draped over your finger and wipe it clean. I held the butterfly valve open with another finger.
Hope this helps.
Hope this helps.
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