Car not returning to stock - all dash lights

[Leibo99]

Hi,

This is my first post and it's going to be a bit long, but I need help with a problem I've had for years and want to give as much detail as I can.

I have a 2017 Civic Hatchback Sport Manual with a 1.5L T engine. The only engine mod I have is a Mishimoto Air Intake.

I have had the Hondata tune for several years and have run various versions of it. Most recently (a year or two) I have kept the calibration to the base map or on a few occasions set it back to stock in the options menu. The reason for this is I keep having an issue where the car will start to bog down/rev bounce while the rpms are coming down while in gear and the throttle is "snappy" when depressed and seems to have a slight delay and then grab a little hard. Sometimes the car will also smell of sulfur (rotten eggs smell). With these issues, all of the dash lights come on as well. Check engine, traction, steering, and brake system. My solution has just been to tune it to base or set back to stock, but then every few weeks or months, it happens again, sometimes even a day or two after I "tune" it.

I stupidly took it to the dealer a few years ago before contacting Hondata and they said I needed a new PCM and charged me $300 just for diag... after I reached out to Hondata, they told me to tune to base or stock and then clear all the DTCs. I have of course done this a few times, clearing all the DTCs when the issue persists, but it won't go away.

I am at a loss for what to do as I am not familiar with the actual technicals of tuning. Most recently the car wouldn't rev past 2k while I was on my way home and I had to coast to a side street. There was power but it was limited and it had that sulfur smell again. I set it back to the base calibration which I have loaded on my Flashpro and got home fine but it still felt like it was driving oddly. I was able to get a laptop to set the car back to stock and clear all DTCs, but it still felt odd. Just two days later, all the lights came back on and I had to tune it to the base yet again.

Also, I don't have anything extra enabled. I am not messing with rev hang or launch control or any of that. Just truly setting it back to stock and leaving it.

Any help is greatly appreciated. I really hope I don't need to replace anything or do repairs as there is other non-engine stuff I need to take care of.

Thanks!

[Spunkster]

When this happens you need to datalog and see what errors are reported.

[Leibo99]

When this happens you need to datalog and see what errors are reported.

I have before and I believe the error was Bank 2 too rich or something like that.

[Spunkster]

You need to get the exact error code it is reporting and then correct that issue. Just clearing the code or reflashing is not going to correct the issue.