C63 Running Weird After Dp and Mini cat install
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AMG C63S
C63 Running Weird After Dp and Mini cat install
Hey guys so recently, I took my car to get a catted DP alone with a Big Daddy Minicat O2 spacer to eliminate the CEL. Due to the CPC and 2021 model year, I didn't want to tune my car just yet. After the Dp install, the car sounded great but felt weird while driving. I couldn't tell exactly what at first but I noticed after a few days that my car simply isn't Downshifitng under load. This is more prominent with speed under 45 MPH which is really werid. On the highway if i deep press the gas peddle in sport plus, it will downshift a few gears no problem and give me the max power. Now if i do this under 45 mile per hour, sometimes I can be in 4th gear with WOT and sport plus mode, and it woulnd't even downshift. it would pull through the entire 4th. Even when I try the kick down, it will go from 4th to 3rd, not even into 2nd. This is super weird, and the only thing i can think of is the MINI cat spacer causing the dp or ECU to detect inaccruate airflow thus restricting the power in lower speed? I have no clue what is going on and prob going to try to remove the mini cat next weekend to see. Has anyone got a similar situation or idea of whats going on? Thanks for any input.
PS: I have tried to clear codes, there is no codes stored in the TCU or ECU. I also tried to do transmission relearn and didn't seem to help at all.
PS: I have tried to clear codes, there is no codes stored in the TCU or ECU. I also tried to do transmission relearn and didn't seem to help at all.
Last edited by PrinceH; Mar 11, 2025 at 08:30 PM.
