i have put my 94 ls400 in the shop to get a diagnostic check on my car because of when i want to pass or accelerate,it starts to bucking like a horse,if i drive it normal,it drives fine.i've read the threads here on CL to do a tune up,(plugs wires,dist.cap,rotors)did that and it still does the same thing!the mechanic checked it again with another portable code reader and it pulled up the 24/ air flow meter/open and short,31/air flow meter circuit open or short,41/ t.p.s i have switched out the tps sensor,the mass air flow sensor and still with the same results!i have inspected the trunk wires but they are fine!i thought it was the gas i've put in a week ago and didn't drive it until sat afternoon 1pm thats when all this occurred!i've ran all the gas out, put in super unleaded along with a can of seafom.still the same thing!!i haven't checked out my ignition coils yet to see if they are the cause or the accordian piece of rubber on mass air flow!i have no choice but to take it to lexus to let them to figure it out!!today i will check my plugs again!also,can anyone tell me were the air temperature sensor and air flow meter is located???

 

i would have thought it to be the knock sensor code

 

Sounds like your hitting the rev limiter like the ecu is running in safe mode because of all your codes. Sometimes when you have several codes like that then you could have a wire issue with a common wire/ground that they all share. Was anything done to it before all this happened?

The AFM (air flow meter) is sensor on your intake.

 

I had the same issues with mine last week. It started after I went through a car wash with under body wash.
The next day it was fine again.

 

Usually when symptoms of multiple failures take place so suddenly, the ECU is almost always involved.

 

thanks for the info.where is the ecu located at and how to reset it back to operating condition again?do i need a code reader or scanner to reset or take it to lexus to do this???

 

none, so far i've filled the car with gas late that evening and drove it home with no problem then when i've left home that afternoon it felt like it wasn't going anywhere when i've gave it the gas to pass car!!!i have my mechanic check all the groung wires,the ecu and the knock sensor looked at,tomorrow!!!

 

well the ecu is a last resort type of thing, there is no test to see if its bad, certain things need to be tested and its a matter of process of elimination to get to the ecu being bad, as far as the knock sensors, they would throw a code

 

To GRAND_LS 4, Forum Moderator:

How do I send a private message to someone? I only want to send the message to one person but it won't send the message because I don't know who or what "BCC recipient" is. Unless that line is filled in the message won't be sent.

Any help you can provide in straightening me out on the subject of private messages will be greatly appreciated.

 

type in the user's screenname as it appears next to their posts (proper case and all)

 

or just click their name, a drop down menu should occur and u will see, send private message.

 

One thought: So many plastic and vinyl parts are will be showing signs of having been exposed to the under hood temps and age causes changes as well. I encountered similar issues when our Cressida got beyond 15 years old. Lots of plastic was becoming brittle as were parts of the wiring harness. Add to that the vacuum lines...it is a mess to track down.

One day I bought vacuum lies and began replacing them one-by-one. Also replaced a variety of affordable sensors and when done...the car was happy again.

 

Exactly what they said. Thanks guys.