JB4 Mobile

it is not worth it as it's not connection doesn't work

Oct 10, 2026

Can't Login. I am totally locked out of the app. I have turned bt off and on, no effect. I have uninstalled and reinstalled the app and I am still locked out. I have used the forgot password link and encountered an error occurred. I have tried to establish a new account with a different email and got an error message. The customer service is nonexistent. I have had problems with my car burning out coil packs and even though I have replaced the coils, I don't dare drive my car without logs.

Oct 6, 2026

paid for the app and wasn't even able to use it. bought a Kia stinger gt2 that had a jb4 installed in it previously but was unable to connect to it cause the previous owner still has authority over it. sent in multiple requests to get authorization for the jb4 module on my own car and never heard anything back. I eventually found out the jb4 was also causing over boost issues on my car. even if I bought the car without a jb4 I don't think I'd buy one after this experience.

Sep 30, 2026

not sure why there are so many bad reviews. my Genesis was the first car I've ever had with power that I can modified. I put 15k into my car and I did all the work with no experience including the jb4 with methanol injection and ewg wires along many other things. the jb4 app works perfectly fine and I've never had an issue with connecting or it not reading certain things. I can tell you after installing it I have no doubt that others installed it incorrectly and I can almost guarantee you that

Aug 2, 2026

Current version is stable and has nice base of features brought back from the original and new features, been very pleased with it been using JB4 since 2019.

Jul 11, 2026