Purchased Modified Stinger. Complete Newbie to Modding. Need advice

[Jake630]

Hi Everyone!

I would appreciate some help in understanding the vehicle I purchased and what the previous owner may or may not have done to the car. A year ago, I purchased a used 2021 Kia Stinger GT2. I knew nothing about performance modifications or tuning before purchasing the vehicle and was unaware this vehicle was modded when I purchased it. I have fallen down the research rabbit hole and am not sure what to make of it and could use some help from experienced folks. From my own research and visual inspection, here is a list of modifications that were done to the car as well as some assumptions:

BMS cold air intakes
HFC Down and Midpipe combo kit (not sure if any of the rest of the exhaust system was modified)
JB4 piggyback tuner with EWG and fuel wires

Based on the above, I would assume the previous owner also installed either HKS or Denso spark plugs with recommended gapping.

When I found out about the tuner, I purchased and downloaded the app, and took over ownership. I noticed the previous owner had the JB4 set to map 6, and the custom user adjustments seem nuts. I am a new user so cannot post images and links, so I will describe the user settings below. Curious which if any of these settings impact all maps or if I disabled any foolishness by moving to map 0. If these settings are crazy, please help point out which I need to change and what I need to change them to. I have seen in many forums that the HFC down and midpipes require tuning for overboost control. Do these settings seem like the guy knew what he was doing and was working with a professional or was this some whack job that pushed the engine to the absolute max and dumped it off at a dealership for the next owner to deal with?

I set the tuner to map 0 when I got it and have always run 93 octane pump gas. Vehicle has since had a few problems listed below:

• vehicle burns oil at a rate of approximately 1.5 quarts per 3000 miles. On some accelerations, blue smoke will exit exhaust for a short period then will resolve. Greasy black residue on exhaust tips
• driver side catalytic converter may be failing. I get a frequent P0430 CEL code. This could be due to the ECU not being tuned to the HFC, but if that were the case, shouldn't I be getting a code for both cats? I am thinking most likely case is there is some sort of oil burning issue on the driver side cylinders that has damaged the driver side catalytic converter
• Recently on hard accelerations (jump to above 4000 RPM) car will shake, sensation almost feels like rear tires are rapidly gaining and losing traction. This will cause limp mode and a CEL. The JB4 will say "no codes" when trying to read the CEL, CEL will go away and car will run smoothly after it is restarted. I am thinking this is an intermittent misfire. I have an appointment this week to get the spark plugs and coils inspected and changed if need be
• car is low mileage, approximately 37k at the time of this post. I have put about 15k miles on it since I have purchased it

If anybody is able to help a newbie out your time would be greatly appreciated. This has been my dream car since it came out, and I would hate to get rid of it. My goal is for this to be a fun, sporty daily driver. I have no interest in chasing faster 0-60 or 1/4 times, racing, or taking this to the track. With all of the mods in mind, how do I run this as safely as possible?

JB4 Custom User Adjustment Settings
Boost Menu
All RPM ranges set to 36.0

Fuel Bias Menu
all RPM ranges set to 8

Duty Bias Menu
all RPM ranges set to 7

Opt

• Boost Failsafe PSI: 36.0
• Default Wastegate Pos.: 0
• PID Gain: 30
• Auto Shift Boost Redux: 90
• FF/Wastegate Adaption: 60
• Fuel Open Loop: 0
• Meth Safety Mode (0-3): 0
• Meth Trigger Mode (0-3): 0
• Boost Redux 1st (0 disables): 0.0
• Boost Redux 2nd (0 disables): 0.0
• Boost Redux 3rd (0 disables): 0.0
• Future Use A: 0
• TMAP Setting: 1
• IAT Spoof: 0

 

[Snicklefritz]

Ima bone stock guy. But I enjoy reading others' experiences and slowly learning some things. So, I am subscribing to your thread. There are a lot of modders on the forum. But most of them are not currently active, which means most of them have moved on to their next "projects" and have sold their Stingers. Nevertheless, you should get some good response pretty quickly.

 

[Plakchup]

Whoa those settings look alarmingly wrong and could cause some serious issues!

Boost failsafe should not be above 24 psi! And wastegate adaptations needs to be lower than 50 for sure with those high flow cats. More likely closer to 40 though each car can be different. PID default is 20. Auto shift boost redux default is 60. On mine the fuel duty bias is the 50 across all rpm range and that is the default setting that I would not mess with unless I knew what I was doing. Fuel open loop default is 60. These are the settings on mine with stock primaries and catless secondaries with catback. No cpi or meth. I would have to look at my jb4 and see what the stock boost menu is set across all rpm ranges. Map 6 is the custom map and something I would never touch unless I knew exactly what I am doing.

I would stay away from map 6 and run map 1/2 with the 93 fuel and change out the plugs to new hks ons properly gapped to 0.022-0.024 once you visually inspect them and see if they need to be replaced. It's a fairy cheap good idea anyway to just replace them in case one is giving issues.

Oil burning can be from different issues but it might be from not enough back pressure or worst scenario is the turbo seals leaking. Usually what some owners do is add some cats after the primaries/secondaries or you could just put back the stock secondaries. This is also a reason I am hesitant in changing out my primary cats to high flows because mine is my daily and the last thing I want is headaches with oil burning issues. Even with stock primaries you will still likely burn a small amount of oil but yours sounds like its higher amount not too sure. Mine was just a bit lower since I waited too long to change it (5000 miles). I changed to liqui moly and it's been great since then and now I do mine around 4000 miles. Amsoil is also very good.

You could also remove or disconnect the jb4 and see how she runs but likely it will overboost. Anyhow just sharing my experience. Others might have some more insight they can share as well.

 

[Jake630]

Whoa those settings look alarmingly wrong and could cause some serious issues!

Boost failsafe should not be above 24 psi! And wastegate adaptations needs to be lower than 50 for sure with those high flow cats. More likely closer to 40 though each car can be different. PID default is 20. Auto shift boost redux default is 60. On mine the fuel duty bias is the 50 across all rpm range and that is the default setting that I would not mess with unless I knew what I was doing. Fuel open loop default is 60. These are the settings on mine with stock primaries and catless secondaries with catback. No cpi or meth. I would have to look at my jb4 and see what the stock boost menu is set acdoss all rpm ranges. Map 6 is the custom map and something I would never touch unless I knew exactly what I am doing.

I would stay away from map 6 and run map 1/2 with the 93 fuel and change out the plugs to new hks ons properly gapped to 0.022-0.024 once you visually inspect them and see if they need to be replaced. It's a fairy cheap good idea anyway to just replace them in case one is giving issues.

Oil burning can be from different issues but it might be from not enough back pressure or worst scenario is the turbo seals leaking. Usually what some owners do is add some cats after the primaries/secondaries or you could just put back the stock secondaries. This is also a reason I am hesitant in changing out my primary cats to high flows because mine is my daily and the last thing I want is headaches with oil burning issues.

You could also remove or disconnect the jb4 and see how she runs but likely it will overboost. Anyhow just sharing my experience. Others might have some more insight they can share as well.

Thank you for the information sir it is greatly appreciated! Luckily, I really haven't driven this thing to the max since I got it. I only did 4 total launches on map 0 recently so hoping I didn't blow anything up.

I reverted settings back to default like you suggested, just had a few follow-up questions:

For the wastegate adaptations, I set these to 45 since you said you'd probably have them set between 40-50. What does this setting do? If making the adjustment to 45 is correct, how will I know my car is responding well?

Also, you mention "fuel open loop default is 60". Is that the section that is just labeled "fuel" in the user adjustments menu?

 

[Plakchup]

Man those settings gave me the scare hah!

The fuel open loop is under user adjustments in the "Opt" settings tab. The wategate adaptations basically changes how quickly the wastegates adapt to the increased airflow. They do have limitations. Usually owners tend to go with backend flash when they change out primaries since it dials things in better than just jb4 alone can do. Plus overboost is handled far better as well from the feedback ive gotten since it increases the safety limits and just manages it better than ewg wires. Once you go backend flash you use jb4 still mainly as a boost controller on how much power you want. The bef will do everything else better than jb4 with fuel and ewg wires which at that point you do not need. Some still choose to use the ewg wires I believe. I am about to do the bef myself so I am still learning.

The best way to know how your car runs is to do a log. Do a wot pull on 3rd gear thru 4th or 5th entirely in mexico or safe area. Jb4 will log automatically once you stomp throttle beyond 90% unless its changed in the log settings. But first see how things run with these settings and try to change to liqui moly or ams oil before you go WOT again. I use 5w-40. Works great! Engine chatter is much less and smooth too. Mine pulls like a beast on map 3 with e30 blend. I sometimes go back to map 2 with 91 only for 1 or two fill ups, then back to e30 just to keep car happy with the detergents from the 91 only.

 

[Jake630]

Man those settings gave me the scare hah!

The fuel open loop is under user adjustments in the "Opt" settings tab. The wategate adaptations basically changes how quickly the wastegates adapt to the increased airflow. They do have limitations. Usually owners tend to go with backend flash when they change out primaries since it dials things in better than just jb4 alone can do. Plus overboost is handled far better as well from the feedback ive gotten since it increases the safety limits and just manages it better than ewg wires.

The best way to know how your car runs is to do a log. Do a wot pull on 3rd gear thru 4th or 5th entirely in mexico or safe area. Jb4 will log automatically once you stomp throttle beyond 90% unless its changed in the log settings. But first see how things run with these settings and try to change to liqui moly or ams oil before you go WOT again. I use 5w-40. Works great! Engine chatter is much less and smooth too. Mine pulls like a beast on map 3 with e30 blend. I sometimes go back to map 2 with 91 only for 1 or two fill ups, then back to e30 just to keep car happy with the detergents from the 91 only.

I know right! I don't know much about that stuff, but it even made me scratch my head. Hopefully I just need some new spark plugs. Car runs perfectly smooth at cruising RPMs, just doesn't like that extra "oomph" that kicks in when you push the pedal past 50%. Only ever got that intermittent CEL with no codes when accelerating hard, perhaps the stock ECU noticed something wonky and put the car into limp to protect it.

I appreciate your insight, enjoy your stinger!

 

[Plakchup]

No problem. That P0430 code is common when you go high flows or catless. Could also be the o2 sensors but from what I read people get it and just delete the code. The stock ecu basically doesn't see oem cats operating range and triggers a CEL. Bef is likely the better route to not have that come back. But yeah I have limited knowledge about those high flow cats but common issue is that they keep causing CEL until you go for a real ecu tune or bef.

I would go one step at a time and just see how she runs with some small changes one at a time before doing more modifications.

 

[Jake630]

Thank you for the information sir it is greatly appreciated! Luckily, I really haven't driven this thing to the max since I got it. I only did 4 total launches on map 0 recently so hoping I didn't blow anything up.

I reverted settings back to default like you suggested, just had a few follow-up questions:

For the wastegate adaptations, I set these to 45 since you said you'd probably have them set between 40-50. What does this setting do? If making the adjustment to 45 is correct, how will I know my car is responding well?

Also, you mention "fuel open loop default is 60". Is that the section that is just labeled "fuel" in the user adjustments menu?

Hi Plakchup. Sorry to ask again, just wanted to make sure I was clear. These are the "fuel bias" settings the previous owner had set. Should these be set to 50 along with the duty bias settings?

 

[Jake630]

No problem. That P0430 code is common when you go high flows or catless. Could also be the o2 sensors but from what I read people get it and just delete the code. The stock ecu basically doesn't see oem cats operating range and triggers a CEL. Bef is likely the better route to not have that come back. But yeah I have limited knowledge about those high flow cats but common issue is that they keep causing CEL until you go for a real ecu tune or bef.

I would go one step at a time and just see how she runs with some small changes one at a time before doing more modifications.

Hi Plakchup. Just got permission to post attachments in the forum. Below is a picture of the "fuel bias" settings the previous user had set (green sliders). In your initial response, you said to set the fuel duty bias to 50 also pictured below (red sliders). I set both to 50, but want to make sure I was understanding correctly.

 

[Plakchup]

Yeah that's definitely strange those settings. Here are my settings. I have the ewg wires. No cpi or wmi. Hope this help in getting yours to run better and that oil burning to stop. From what I've learned the oil burning starts when you go catless primaries and secondaries.

 

[Daniel @ K8 Stinger Store]

Welcome to the forum!

Sounds like you picked up an absolute beast of a Stinger.

One of the good things about BMS is that you can send over your logs and they can help you dial all this in.

We have a great relationship with the guys over there as they are neighbors to our new store location.

If you want to continue on the mod train and have any questions feel free to reach out to us any time.​

 

[Thomby]

I agree with all of @Plakchup's settings. My recommendations (as someone who's run E30/Map 5 for a couple years):

- Pull at least one plug (ideally all 6) to confirm it's a step colder, and gapped properly
- With default settings and Map 0, do a rest run a check your logs
- If you're running 93 octane, repeat with Map 1 and Map 2
- Get an OBDII reader and check for stored codes -- I think JB4 may only capture them while the app is open or during a log, as I've had codes that didn't show up in the app

After that, if the oil burning bothers you or you want to confirm it's not something else, I'd consider swapping the downpipes/midpipes back to stock. Otherwise, if you have E85 available and want to try an E30 mix, try Map 3 & 4 once you're comfortable reading logs.

 

[Jake630]

Yeah that's definitely strange those settings. Here are my settings. I have the ewg wires. No cpi or wmi. Hope this help in getting yours to run better and that oil burning to stop. From what I've learned the oil burning starts when you go catless primaries and secondaries.

I appreciate you sending this over. I got my settings to match yours and now feel much more comfortable. Taking it to the shop to check on the intermittent misfire issue, hoping it is just a plug that needs changed. Do you know why the catless downpipes would start causing oil to burn out of curiousity?

 

[Jake630]

I agree with all of @Plakchup's settings. My recommendations (as someone who's run E30/Map 5 for a couple years):

- Pull at least one plug (ideally all 6) to confirm it's a step colder, and gapped properly
- With default settings and Map 0, do a rest run a check your logs
- If you're running 93 octane, repeat with Map 1 and Map 2
- Get an ODBII reader and check for stored codes -- I think JB4 may only capture them while the app is open or during a log, as I've had codes that didn't show up in the app

After that, if the oil burning bothers you or you want to confirm it's not something else, I'd consider swapping the downpipes/midpipes back to stock. Otherwise, if you have E85 available and want to try an E30 mix, try Map 3 & 4 once you're comfortable reading logs.

Thanks for the reply sir! Definitely feeling more comfortable with these settings! Won't be able to really put it to the test until I can get the plugs and coils looked at for that intermittent misfire issue, but this should really help. Sounds like your stinger is a beast!

 

[Thomby]

Do you know why the catless downpipes would start causing oil to burn out of curiousity?

Several people who've swapped downpipes & midpipes have reported blue smoke. The theory is that the turbo oil seals are sensitive to the change in pressure across them, so instead of draining back down to the pain, some of the oil works past the seal and out the exhaust.

I think most reports have been small/intermittent amounts of smoke, which don't bother some people. But 1.5 qts per 3000 miles, at 37,000 miles on the odometer, would concern me a bit. Might be worth seeing what you can find a stock set for, and seeing if it's all from the aftermarket pipes.

But for now I'd check the plug (model + gap), pull codes with a dedicated reader, clear them out, and see if anything comes back over the next couple weeks.

 

[Jake630]

Several people who've swapped downpipes & midpipes have reported blue smoke. The theory is that the turbo oil seals are sensitive to the change in pressure across them, so instead of draining back down to the pain, some of the oil works past the seal and out the exhaust.

I think most reports have been small/intermittent amounts of smoke, which don't bother some people. But 1.5 qts per 3000 miles, at 37,000 miles on the odometer, would concern me a bit. Might be worth seeing what you can find a stock set for, and seeing if it's all from the aftermarket pipes.

But for now I'd check the plug (model + gap), pull codes with a dedicated reader, clear them out, and see if anything comes back over the next couple weeks.

Thanks for the info, that makes sense. Biggest hurdle is finding some stock catalytic converters lol. Used market looks okay for them, will have to keep that in mind and save up.