Question on new truck harsh shifting and code then P0420

[JustDennis]

I just got a 2017 SCREW with 31K miles about a week ago. It had all the options I wanted and looks brand new. The previous owner added several options that I was happy with - powered bed cover, Magnaflow D exhaust, Whipple Cold Air Intake, tinted windows, maybe more. I introduced myself in the new members section with some other details.

When I got the truck I noticed that the shifting was very harsh and abrupt at times. It sometimes seemed hesitant as well. The truck was almost undriveable in Sport mode due to the hard shifting. I also noticed from the carfax that there was an outstanding recall on the seat belt. I did some research here and found there was a TSB for the shifting. First cleared the adaptive tables and it got better but not where it should be. I called the dealer and made an appointment. They were very cooperative and did the recall and applied TSB 18-2079. This fixed the shifting but also brought back the auto start/stop function. I was guessing the previous owner had either done a tune or turned that off with forscan so I was kinda expecting that.

Last night while driving (next day after service) I got a check engine light. Pulled the code - P0420. Now I'm wondering if there is a problem with the cat or O2 sensors or is this a result of the dealer reprogramming the ECM and the Magnaflow exhaust and Whipple CAI. ANy thoughts or suggestions are welcomed. I cleared the code and am waiting to see if it comes back but wondered should I be checking something or looking for a tuner....

Anyway, the shifting is much better. I turned off auto stop/start and a couple of other things (Double honk, numbers over temp) with Forscan. Overall really happy with this Raptor if I can get rid of the code. Thanks in advance for any advice.

 

[Traffic22]

I believe it is two different sets of programming. The shifting is controlled by the TCM, the engine by the ECM/PCM. Did they re-flash your ECM/PCM to the most current version too?

I bought an 18 about a month ago, had the same rough shifting, brought it in and had the TCM done, and paid to have the newest version of ECM/PCM done as well. No codes or check engine light, but I also don't have the mods you do.

 

[Antho]

Mine shifted like crap until i reset the PCM and the TCM. Shift like butter now. Not sure about the code. Once cleared has it came back?

 

[FordTechOne]

If the previous owner had installed a tune, especially a cheap plug-and-play one, it may have resulted in over fueling and damage to the catalytic converter. The easiest (cheap) way to keep a turbocharged engine alive at increased power/boost levels is to run it overly rich. Rich A/F mixtures result in an incomplete fuel burn which must then be dealt with by the catalyst. This causes catalyst temperatures to exceed threshold, resulting in catalyst damage and efficiency DTCs such as P0420.

 

[isis]

New O2 is usually cheaper than a new Catalytic convertor. Probably start there.

 

[Booth9999]

Still under warranty for power train until 60,000k

 

[robert berry]

the dealer wiped out your tune, same happened to me, had to put it on the dyno and get it re tuned .

 

[JustDennis]

If the previous owner had installed a tune, especially a cheap plug-and-play one, it may have resulted in over fueling and damage to the catalytic converter. The easiest (cheap) way to keep a turbocharged engine alive at increased power/boost levels is to run it overly rich. Rich A/F mixtures result in an incomplete fuel burn which must then be dealt with by the catalyst. This causes catalyst temperatures to exceed threshold, resulting in catalyst damage and efficiency DTCs such as P0420.

I cleared the codes and have been driving some for about 3 days. Service engine soon light came on so I checked codes again. I’m getting both P0420 (bank 1) and P0430 (bank 2). I’ll crawl under the truck and take a look. I thought the PO installed the Magnaflow D-Fit Kit but need to double check that is all. I don’t like the current sound anyway so may end up changing.


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[JustDennis]

the dealer wiped out your tune, same happened to me, had to put it on the dyno and get it re tuned .

So do you think the tune had turned off these codes or is it something new?


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[JustDennis]

So I think the PO installed the full Magnaflow system. Took this from under the truck. Does this look like stock cat or not?


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