[Yakamoz]

Hello,

I am going to be a tad long winded because I don't know what I am doing so have no idea what is relevant.
***Background/History***
I recently bought a 2015 BMW 335i. The guy before me had done the charge pipe, muffler delete, catless downpipe, and a mhd stage2 91 octane tune. I installed a vrsf 5" FMIC and put in a AFE air filter. I bought an MHD license yesterday switched two a stage 2 93 octane map and logged the car. https://datazap.me/u/yakamoz/saturda...29-30-31-32-33. Saw that my timing correction for the cylinders was horrible bought NGK 97506 spark plugs and replaced them with a gap of .022. Apparently, the guy before me was still using the stock Bosch spark plugs. Logged the car again -> https://datazap.me/u/yakamoz/log-165...41-42-43-44-45. The timing does look okay I think even though there is still some correction. This time I noticed the boost target and actual boost were not even close. BTW my log reading is going soley off this https://www.docdroid.net/IyQ24N5/int...ogs-pdf#page=6

***Problem***
Now when I was logging after replacing the spark plugs, I got a drive train malfunction, which disappeared after I turned the car on and off. Used the MHD DME reader to read the code which was "120308 - Charging pressure control, plausibility Pressure too low." Anyone know what this is and how I can go about fixing it. Also, if you see other problems with my logs, please let me know. I've been a car person for all of one week at this point, so I am lost and slightly scared lol.

93 Tune Logs
https://datazap.me/u/yakamoz/93-tune...ta=3-4-5-21-67
91 Tune Logs
https://datazap.me/u/yakamoz/91-tune...43-44-45-46-47

Any guidance will be much appreciated!

[SuperLomi]

I think that code is usually associated with a boostleak. Clear it and see if it comes back. You may want to do a boost leak test - I’d suspect something possibly leaking where you installed the IC.

Also, fwiw, you probably don’t need colder plugs, and you may want to consider swapping back next time you change them out (bigger spark is generally better for combustion). Stock plugs should be fine for all the OTS gas tunes. I’d only go colder if you have specific symptoms of overheating plugs.

[thejeremyman9]

1. You want stock bosch plugs, not colder NGKs with a smaller gap. Dont listen to the online recommendations.

2. You need to collect a "proper" datalog, read my thread here: https://f30.bimmerpost.com/forums/sh....php?t=1732327

3. Your log is missing manifold boost, so you need to add that as a parameter. Load and boost are a bit below target, but you started in 3rd gear. Again collect a proper log as above.

4. You may need to run 91 map with 93 fuel, very common, but need a set of 3 proper logs to evaluate.

[Yakamoz]

Originally Posted by SuperLomi

I think that code is usually associated with a boostleak. Clear it and see if it comes back. You may want to do a boost leak test - I’d suspect something possibly leaking where you installed the IC.

Also, fwiw, you probably don’t need colder plugs, and you may want to consider swapping back next time you change them out (bigger spark is generally better for combustion). Stock plugs should be fine for all the OTS gas tunes. I’d only go colder if you have specific symptoms of overheating plugs.

Went with those plugs after seeing a bunch of people on YouTube switch to them for their tune. Guess I'll switch back next time I change them so in like 15k miles?

How would you recommend doing a boost leak test? My current plan is renting an air compressor with a gauge, sticking a connector on to a pvc cap and sticking it into where my air intake normally goes which would be the turbo inlet, I think.

[Yakamoz]

Originally Posted by thejeremyman9

1. You want stock bosch plugs, not colder NGKs with a smaller gap. Dont listen to the online recommendations.

2. You need to collect a "proper" datalog, read my thread here: https://f30.bimmerpost.com/forums/sh....php?t=1732327

3. Your log is missing manifold boost, so you need to add that as a parameter. Load and boost are a bit below target, but you started in 3rd gear. Again collect a proper log as above.

4. You may need to run 91 map with 93 fuel, very common, but need a set of 3 proper logs to evaluate.

After reading your post more carefully on how to read logs and looking at my logs again it seems like everything is within range aside from my boost not hitting its target. It seems like I have a lot less correction with the 91 octane tune so I'll be sticking to that. Going to try doing the smoke test method if I can find a reasonable priced one. Thank you so much for the write up!

[thejeremyman9]

Originally Posted by Yakamoz

Went with those plugs after seeing a bunch of people on YouTube switch to them for their tune. Guess I'll switch back next time I change them so in like 15k miles?

How would you recommend doing a boost leak test? My current plan is renting an air compressor with a gauge, sticking a connector on to a pvc cap and sticking it into where my air intake normally goes which would be the turbo inlet, I think.

I describe in detail here how to build a home made pressure tester https://f30.bimmerpost.com/forums/sh....php?t=1621695