YotePower

Good afternoon all! This is my first post to this site. Earlier this year I purchased an '18 GT Premium. Shortly thereafter, I installed a Rousch cold air intake and took it to a local shop that prides themselves on tuning Mustangs. First off, I will admit this is not a daily driver (I drive it on average 1x/week). However, every time I have driven the car it has thrown the yellow wrench and the car essentially cuts almost all power and I'm forced to limp my way to safe area and reset the car to factory stock. I consulted with the dealer, as well as Dallas Mustang and both have advised that the wrench means it's a throttle body issue. The installer of the tune just keeps telling me to bring it in "again" and they'll "try" to figure it out. Also, I'm of the understanding that the new '18 GT with the 10-speed automatic is to have somewhere between 435 and 465 HP. After the tune, they told me that the car was only producing 417 HP.....how can this be? I'm pretty novice when it comes to these types of workmanship issues, so I'm just looking for some more guidance and advice on next steps. THANKS!!

Mdfitnc

Did it have any issues pre roush cai? What kind of tuner?

YotePower

No issues at all prior to cai. It is a CST tuner I purchased from the folks that did my tune/dyno.

Dr Plastic

A few questions...

1. Who did the install?
2. Did you get the CAI from Roush with the Roush PCM flash
3. Was the restrictor tube installed in the intake tube?. If so then the tune you were sent is designed for the larger intake trunk and if it was installed, may be the source of your problems.

Rpinaiii

The 417 HP I am thinking that may be rear wheel HP. Double check that

Grayghost5.0

Its your tune, if you dont have a tune keep the insert in.... if youre having a issue with the tune keep the insert in .... data log and send it to them ... I had a HUGE issue with Bren Speed and the Roush CAI.... the BEST tune to use with a Roush CAI with the insert removed I have their 93 Performance and Race tune and their 91 Performance tune with NO issues what so ever. Brenspeed my car ran lean with the insert removed ...then ran perfect with the insert in, and since I want optimal performance I want that insert removed ...if I wanted to keep the insert I would have kept the stock tune. Brenspeed sent me a revision tune and my car wouldnt run at all kept dying on me and shutting down, they told me they are having an issue with the intake...... so I dumped them and stuck with Bama for the tune...my car runs like a raped ape with the Bama 93 tune and the Roush CAI ...

juliansloan

Hey Grayghost! Are you doing the Bama tune without the inner tube to make it run? Thanks!

Bert

Hi Julian, welcome to the forum - the key here is that the tune MUST match the intake, If you use the "inner tube" then you need a tune that is designed for that (I believe that is designed to work with factory tune); if you remove it, then you need the tune for that. This is because the diameter of that tube is part of the math that the computer uses for the electronic fuel injection; and if that math is wrong, then the car won't run right.

m05fastbackGT

In other words, if the inlet tube's MAF diameter is larger than OEM stock, the aftermarket tune must be designed for the aftermarket inlet tube's MAF diameter, otherwise, the vehicle's air/fuel ratio will be way off and won't operate properly... If the inlet tube includes an insert mimicking the stock diameter of the MAF housing, an aftermarket tune is not required if the insert is placed inside the inlet tube of the CAI...

Grayghost5.0... Also just a heads up, the last thread activity was from over 3.5 years ago, therefore, I wouldn't count on receiving replies from any of the original posters