I spoke to a technician at Tuning Technologies in Colton, CA. He explained that installing NEO unit wouldn't be necessary. According to him, all that's needed with my headers and exhaust is the re-programming of the ECU. Has anyone had any good or bad experiences with ECU re-programming with the 98GS4? The tekkie told me there's no long term damage to the car by doing so, but I would like to hear from ones who've actually done it. Any thoughts?

 

From the sound of it the guy was doing alot of assuming. Some cars you can reprogram the ECU some you cant. The lexus ecu is encrypted as far as i know no one has ever been able to break the encryption on it there for the ecu can not be tuned. I think you should tell him about the encryption and see if he still says he can do it. If he does tell him you will pay him if he can do it successfully and you wont if he cant. If he could tune the ecu he could take off the governer change timing and adjust the redline and change the a/f ratios as well which would be extremely cool.

 

I think if the ECU was able to be just be re-porgramed, more forum members would have gone this route instead of using the neo.

 

Jet tried to do it for the GS 8+ years ago.

If they were not successful, that tells you something.