Scionlife.com - TRD S/C detune

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This is my first post

I recently bought a 2006 Scion tC as a fun car to drive once in a while. It had a TRD supercharger that didn’t work and was disconnected by the pulley, but still connected by the air intake. This would cause the car to crank longer than usual but when turned over,
it stayed on and idled with 700 rpms. but besides that, it was in good condition and shape, especially the engine, according to the mechanic I brought with me.

Fast forward, I bought it and immediately had the Super Charger removed and installed a 80 dollar eBay cold air intake into the engine and this is where some problems and revelation arises.

Skimming through the car I found out documents and a software device part within that show it was modded. Specifically the ECU was tuned to have a TRD mapping (I'm assuming this was done same time as the Super Charger). There’s also a premium only sticker within the
gas cap suggesting it was tuned for the ECU to prevent engine knock with the Super Charger. I also found a software device with part number “89663-YW201”, that hasn’t been opened. I searched around and it seems this software device might be able to reflash the ECU to stock tuning.

I'm heavily assuming this tuning is causing the car not to run properly anymore with the cold air intake, giving me all cylinders misfiring and engine running lean codes. The car also stalls out now when first started unless give some gas from revving the engine.

My question is how do I best go about this?

The options I’m thinking about are
1. Go to a Tune shop, tell them the situation, show the software device and see what they suggest
2. Buy a used, remanufacured ECU and install it and let the car retrain itself
3. Remove the CAI and put in the stock air intake and see what happens.

TLDR: I bought a car that had a messed up TRD Supercharger and the ECU has been tuned with the TRD mapping for it. Trashed the Supercharger
and put a cold air intake, car isn’t running properly with it now and now thinking if I should get a new reman ECU or get the ECU re-tuned to stock.

*Moved to Correct Forum by Administrator

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I would start by going to a dealer (or at least calling one) and seeing if they can flash it for you. They should have those tunes available seeing as how the S/C was a TRD part they sold.

I did call up a dealership and was informed that a reflash back to stock was impossible and I would have to get a brand new ECU in which they quoted me north of $1,000 and which I promptly hung up the phone.
I ended up getting a used ECU of the same year and transmission from eBay ($50) and doing a programming myself of it through a YouTube video. Car never stalled again but ran rough with a ticking sound from the engine and still had hesitation during acceleration.
I changed the spark plugs and fuel injectors back to stock specifications and the car runs like a clock as of now. All in All cost me a total of about $200 since I got the Super Charger removed by a master mechanic pal.

I hope my situation can help anybody who is wondering about the TRD Supercharger/flash and the best way to go about it to having their car run properly again if they decide to remove it.

On the re-flashed ECU you have. I would buy a ECU from the dealer they are very easy to set up and then sell the re-flashed ECU, You will also want to change the t-stat back to the stock one, so it wont read cold and make you ECU pop a code, one other thing you will wont to change the plugs back to stock.

To be honest, removing the SC should not cause a problem as the MAF sensor would see that there is no additional airflow. Your problems might be just because of your ebay intake, as most of the cheap intakes do not size the piping in the MAF section properly. Try an OEM airbox first. It might run well enough as is.

You wouldn't want to flash back to stock anyways, as the SC kit has larger injectors which will not run well with the stock tune. Unless you have the oem injectors to swap back in, of course.