The chirping began in my car at 300 mile and continued until I moved to Oklahoma from Dallas. Once I started pumpin no ethanol gas at 1500 miles, I've never heard the chirping again.

Chirp started today at about 550 miles... Still faint.. 91 Chevron CA blend.

So I'm am schedualed to have my fuel pump replaced next week, I had a concern after reading the 5009 page repair manual I found on here. So I called the service manager to micro manage and inquire.
Q1 Did they order all the support parts required to replace the pump?
A1 Yes, SOA told them everything they would need to replace the pump since my dealer said it would be the first one they ever did. (wish me luck)
Q2 Since I am still waiting on the ECU from the TSB is it possible that my old ECU will not communicate with TechStream to set the correct PSI for the new fuel pump?
A2 I don't know but that is a possibilty. I will call SOA and see if the TSB on the DLR is more of a TechStream issue than just customization or mainly a Techstream communication issue.
This is where I pray a Toy Tech might chime in define if the TSB is related just to customizations and Other TechStream connectivity?

Experienced chirpping at EXACTLY 300 miles. This was after my first fill up so I'm sure it has to do with the gas. I filled up with premium unleaded at Dillons.

I called my CSR at SoA today noting the Scion TSB, but she hasn't called me...they leave in 30min. Time to bug her, I suppose.

I was told today by a Scion/Toyota mechanic that this is from the 3000psi Fuel pump, and is completely normal.

Shove the printed TSB into his lying face. If you do - stand by and watch him work just in case ;)

SO the Service manager just called me from Beaver Scion to let me know the ECU from the DRL TSB does not control the fuel pump through tech stream, So my car goes in on Wednesday for the new fuel pump. They will not give me a TSB to share with you all, but if it gets printed on my receipt, trust me I'll be posting it here.

New fuel pump heyyyyyyyyyy! Rejoice!

What will this new pump sound like :) ? Maybe a tweet? perhaps a hiss! or fap ! A noise less boring and sleep orienting.

Not the injector
 

My BRZ has about 2.8K miles on the odometer and indeed it's been chirping since fairly early on.
It doesn't personally bother or annoy me as long as it's not bad for the car. Sports car engines sometimes make some very weird noises. They are not made for GT cruising so the engineers don't pay that much attention to it. Also, the BRZ has a special engine. It's naturally aspirated but still delivers 100hp per liter. That's similar to other sports cars like the BMW M3 and Honda S2000 but with much, much better fuel economy. That requires some serious mechanical hacking.

However, I don't think it's the injector's noise since the chirping frequency doesn't change linearly with RPM. You can test it by letting your car idle while paying attention to the chirping frequency and then slightly increasing the RPM. The chirping frequency will not change. If you rev the engine significantly higher the chirping usually stops or just becomes less audible.

I originally voted No, but I finally opened my hood and mine does in fact chirp, but it isn't something that I notice from inside the car. I would have to hear a silent one to say that it isn't normal.

SO my car went in for a fuel pump and this is the car they loaned me to drive. Jennifer in service called and said it should be done by 4:00pm but was unsure as they have replaced on as of yet. Well it shouldn't be that hard to replace, I verified they had all the parts recommended on the TSB in stock.
http://s3.amazonaws.com/toyota.site....kdta3_04v7.jpg

Come on you guys are freaking me out when I hear this. I always said I would never buy a new car the 1st year it comes out to allow them to work out the bugs - in this case a cricket. But I really,really want this car.

it's just a minor annoyance.