Removing post

 

Not much people (or any) have done the RR Racing tune on the 3IS... So.. you're kinda better off getting in touch for RR Racing themselves.

 

That’s a very strange issue. Especially since you said no codes were thrown.

The ECU wouldn’t force limp mode without seeing something that is wrong and it would definitely throw a code then.

Best to speak with RR and get their opinion.

 

Update: reset the ECU last night and drove into work with no CEL, the diagnostic didn't have enough time to run.

I will get in touch with RR.

 

Not necessarily the solution, but I think I read a similar issue on a 2IS where the engine determined it was running lean. The guy had modified the intake pipe. Got rid of the resonator on a f-sport or something and had a vacuum leak. Have you done any mods on the intake? Maybe look around for a loose vacuum line.,

 

No mods on the intake. I will check the lines to make sure they're good. The car did have sustained vaccum pressure and engine temp stayed normal.

 

any update on what caused the issue?

 

Yea​ it was a stupid OBD 2 Bluetooth reader. Literally had nothing to do with the tune. Don't ever drive with that **** on. I took it off and have been smashing on the regular and have had no issues whatsoever.

The tune is awesome and the car's powerband feels much smoother..

 

Update: I just completed a grueling 800 mile round trip to South Texas from Houston. ZERO issues with the tune. No codes, no hesitation, no nothing. I even attempted to do a 0-60 run but failed miserably. This tune is friggin gold and anyone who owns an IS 350 F-Sport needs to get it done.. This is the most bang for your buck, literally....

I am 150% convinced it was that POS bluetooth ECU dongle. Don't buy those things, let alone drive with it on.