qualitech

Sadly no, i need to source a multimeter today so i can check the voltsges for each line. You have a facebook or something so I can message you personally?

Yamae

Modern cars need at least a code reader and a multimeter. So it's good that you are sourcing a multimeter.
The code P0100 and P0101 are both related to the MAF sensor but those include the power source such as the open fuse EFI-No.2, floating ground, failed MAF sensor, open/short wires and etc. That's why it is important to measure voltages to it and from it. Without doing so, you can't judge any.

The ECU makes it possible to run the car even when those voltages are strange to avoid the engine to halt at middle of nowhere. But it limits the maximum engine RPM.

Sorry that I don't use the Facebook nor others since I don't trust GAFAM (Google、Apple、Facebook、Amazon、Microsoft). I don't use the Windows nor Mac OS. I only use Linux for the better and safer life.

qualitech

I respect that facebook got so much scammers for lexus parts. yeah i put the code reader on catching the same exact codes and issue as the original poster hoping the fuse would fix it but sadly nope. im at work right now but itching to get home n look more into itz i was thinkin bout swapping out the main EFI relay with my gs400 one since it was free to do. i dont even know where to start, the diagram you sent earlier shows me each line to test with the multimeter? and if so how much volts it need to read

Yamae

See my post #7 and voltages are as follows.
1 THA: varies on air temperature
2 E2 : 5.0V
3 F2G: 0.0V
4 B : Battery Voltage
5 VG : varies on passing air amount

I usually insert a sewing needle to the insulated wires to measure the voltage. Your multimeter's black prove should be connected to the battery's negative terminal.

qualitech

Thank you! i forgot to mention when i installed a new fuse it blew, put another one in without the battery and it didnt blow. so ima check the connection on my 02 sensor to see if its grounded out there

qualitech

checked under the car no loose wires showing. sadly no extra efi relay to test if the relay, but i will be gettin a multimeter tomorrow.

Yamae

I think you probably know about loads of the EFI-No.2 fuse but I dare write them here.

1, MAF sensor
2, O2 sensors B1S1, B2S1,B1S2 and B2S2
3, Solenoids used for evaporation system. A JDM has 2 solenoids but USDM may have some more due to the strict regulation.
4, DIAG connector

I worry that one of these or these lines must be short-circuited to the chassis/ground.

Yamae

One more item I'd better to inform you. This is about a LS430 but to read this thread may help you to troubleshoot some.
https://www.clublexus.com/forums/ls-...s-to-blow.html

What I mean to say is that P0100 is not always related to the MAF sensor. Above was the O2 sensor's heater related problem. The poster rkw77080 was initially suggesting to check only the MAF sensor seeing the diagram which only shows MAF related lines. But later on he deleted his post since what he wrote was not correct. The EFI-No.2 fuse supplies +B to O2 sensors and others as I posted at #22.