Ok i have another Thread about my 1991 LS not being able to Shift past 4,000 RPM... My Problem on that is not yet solved but i got another Problem now... I Got a check engine light Along side "Trac Off" and "Trac" Right next to the Check Engine light... Are those Traction Control codes?? Or Engine Codes??

 

The "trac" light is used for the traction control codes or it could just be low brake fluid, which causes the light to come on. The "engine" light is for the engine codes. B/c of your other problem, (might be air/fuel mixture) I would think you will come up with a 24 and/or 31 on the engine code which is for the AFM. But, I could be wrong, so check them all out with this link. http://www.lexls.com/tutorials/intro/codereading.html
On a side note; I have my AFM unplugged and the "engine" and "Trac off" lights are on.

 

i will check my Fluid in the Morning! Thanks! and i will get the codes tomorrow and Post again!

Thanks!

 

OK so i got the codes out of my 91 LS And i got code number 25 Air/Fuel Ratio Lean Malfunction.. Any tips as to what it may be?

 

It could be a number of things but looking at my manual it looks like it would be your main heated O2 sensor. Other possibilities would be short in O2 circuit, ignition system, ECT sensor. I thought that it was your AFM but that would make it rich, not lean. I hate trying to diagnos anything b/c there is so many tests ya have to go through to find the correct part that is bad.

 

The ECT Sensor??

 

"Engine Coolant Temp" sensor. It tells the computor alot, mainly how much fuel to deliver. Check out a little of this, or search for more on it. https://www.clublexus.com/forums/ls4...read-this.html As it says in the first post of this link, the Coolant Tempurature Sensor is the "MAIN SENSOR" for the computer. This sensor has more control over the computer than any other sensor.

 

Im going to start by changing that sensor then.