Exactly the 1st thing I thought when I saw "Tune". Step # 1. Return to stock. Test. Then..................... I'm 99% sure its the Tune.

 

At the beginning when the tune was first available you had to send the ECU in to RR. It wasn't until later that the handheld flashing device became available.

I think it's more of the device is married to the car, so you can't flash someone else's car. The device holds the stock file and any tunes that you have uploaded to it.

I've seen Rafi mention in other threads they can sell you a new device for a small fee. As far the stock tune, I really don't know if that is car specific or if they can give you another stock tune if they don't have your specific car on file. They do require you to send in the stock file before receiving the tune file.

 

Big thanks to Rafi!!! I hit him up on Facebook today. He responded immediately and happened to be at the shop. He agreed for me to trailer my ISF up to RR-Racing (2 hr drive each way). He grabbed his computer, did diagnostics on the spot, and figured out the car wasn't tuned at all. He put the tune back on the car and make a few tweaks to get it running great.

The only thing I can think of is Lexus of Towson must have reflashed my car when I took in in for the dash/door panel replacement last year...despite the fact that I have left very very clear and repeated instructions every time my car has gone there that they are not to flash/reprogram/touch the ECU in any way. I believe my car was already on the trailer (from the drag strip) when I took the car to them, and I trailered it back from the dealership as well. So I never drove it long enough for the codes to trip after they apparently reflashed it. Fast forward several months when I actually drove the car again and all the codes popped up, with the subsequent troubleshooting rabbit hole. I'm extremely happy the car is running perfect now. On the other hand I'm pissed at how this all played out over the past 2 years with me not having enough time to get it figured out.

 

Unreal! Glad Rafi figured it out for you!! It's unfortunate you went through 2 years of replacing stuff and trouble shooting just to realize that the dealership flashed it back to stock🤦‍♂️

 

I am glad it is working properly now. Just to make sure there are no hidden fuel delivery issues that were compensated by the ECM re-flashing. Do you know if “voltage drop” checks have been performed on the fuel pump circuit while pump was working? For example if there was resistance in the fuel pump circuit you get the same codes. Loose connections, pitted relay contacts, corrosion etc create unwanted resistance which “steals” needed voltage from fuel pump to deliver proper fuel and engine running lean.
http://www.agcoauto.com/content/news/p2_articleid/331

 

Our circuit isn't so simple. There are three relays between the positive terminal and the fuel pump. Measuring the drop would be very tedious. Also, it's incredibly rare for this kind of fault on any Toyota. Not impossible, but really rare.