AWDSYCO

TPS is located next the the TB, very easy to replace DIY. What happened is the ECU went into "limp mode" and won't allow you to go fast, just barely to get you home.

Possibly you have O2 sensor malfunction. What's car mileage and last time you have TB change?

2000 GS300 186K still running VERY smooth and strong.

Buy this $16 OBD2 scanner to reset your ECU http://www.amazon.com/Autel-MaxiScan-MS300-Diagnostic-Vehicles/dp/B001LHVOVK/ref=sr_1_1?s=automotive&ie=UTF8&qid=1379689217&sr=1-1&keywords=obd2+scanner If you know how to use your phone w/bluetooth, use Torque apps $5 and bluetooth OBD2 adapter is a better choice. All depends how good you are with gadgets. http://www.amazon.com/BAFX-Products-PIC18F2480-diagnostics-compatible/dp/B005NLQAHS/ref=sr_1_1?s=automotive&ie=UTF8&qid=1379689331&sr=1-1&keywords=obd2+scanner+bluetooth