2014 mustang gt roush stage 3...02 sensor issues


Jan 20, 2019
Las Vegas, NV
So...I just purchased a used 2014 roush stage 3...I just rolled to 30k miles. Unfortunately, I'm already having 02 sensor problems. Right after purchasing the car, light came on. I got it scanned. P0430....bad 02 sensor OR at the ford dealer, They say I have a bad cat. In my opinion, I think the car runs like a champ with no miss fires or obvious problems. But im no mechanic, Just a guy who loves cars and mustangs alike. here are some facts (not in any order) about what Ive been experiencing.

1. pulled out oringinal 02 sensor. Looked like it got hot in its past...it was grey and white in some places.

2. Car is completly stock from roush. Stage 3, Phase 1. supercharged, with AXLE back Roush muffler kit and a ecu tune from roush...? (chime in if you know anything about this)

3. I'm already dealing with an UPHILL battle with ROUSH, FORD, the dealer I bought the car from. I have a powertrain warranty that is still good until 5/2019 and besides that, AN emissions warranty good for 96/mo or good for 75k miles or so...Dealers are not wanting to touch the car because they are labeling the Roush add ons as AFTERMARKET. Even though, FORD sells the car the way I have it now as it sits.

4. After a nightmare with dealership visit, and getting robbed 140 bucks to have a diagnosis done that I couldnt believe is true...P0430 translates as a BAD cat...a metal can cannot tell a computer that its not good. It takes a visual inspection, maybe debris in the tail pipe...and overall the car would run like crap (correct me if I'm wrong)

5. I went and bought my own NTK direct fit replacement 02 sensor. (bank 2 is the one Im having issues with. the one after the catalytic converter) After replacement, My light dissapeared for 2 days. My commute to work is about 20 miles round trip. hitting about 50 mph with intersections. I thought I was in the clear for those 2 days....remember I havent paid tax and registration on the car yet.

6. I know what your thinking....This car deserves long tubes and a full job done with a tune. I don't want to hurt my wallet that much if I can avoid it. I'm still trying to get something covered by warranty If I can. New exhaust for this car will be a major hit...Long tubes 700$, mid pipe w/cats another 700...not including installation and tuning :( My goal is to get the car to run properly...If I need a new cat....why? Are these cars prone to early failure? sensors alike? Ive also understood that the stock GT cats may not be suitable for a supercharged engine...And I completely agree If I can get a stock cat for now...just for registration purposes, that would be great. I don't feel like I should pay for it..Warranty is there for a reason, and FORD sold the car like this. Ill keep fighting on and keep the thread updated. Ford, I've heard is the WORST when it comes to warranty work. we'll see.

7. Should I be worried about how the car is running?? It sounds fine....pulls when you want it to. There has to be a mechanical reason for this. I could tune the car now...in its stock form...but thats still around 800 bucks. If I need to, I will.

Thanks for the info in advance. Let me know what you think or if you have any questions.


  • roush and black 19 stang 2.jpg
    roush and black 19 stang 2.jpg
    20.6 KB · Views: 1,186
Last edited:
  • Sponsors(?)


New Member
Jul 13, 2013
If the car has not been further modified from the original Roush modifications it should be honored. Make sure the car does not have an aftermarket tune applied, that could be the root of the problems. If it is setup with original Roush, then you should be able to get it covered. I have a 2014 Roush and the Ford warranty was promised at sale to be fully intact without question. I have only had mine serviced at the local Roush authorized dealer where I purchased. I have not had any warranty issues. Of course mine is a stage 2 and not supercharged, but I know the Stage 3 were also to be fully covered by the Ford warranties from the factory. It was a big saling point for purchasing a Roush in the first place. You will likely need to find a Roush authorized dealer, but all the Ford warranties should still stand. You might want to reach out to Roush Performance if you continue to have problems with the car. Best wishes on getting the beast running right.