Overboost, misfires, AFR all over the place

Hey guys, I am new here, so I apologize if I'm not doing this right...

So, a while ago, I was driving around and punched the throttle, car overboosted to 30psi and hit fuel cut, tried slowly easing into boost and heard the EWG open a little bit, but not nearly as much as normal, the next pull the EWG did not open at all, and car would always overboost. I drove the car like this for about a week, making sure to never go too far into boost, and always checking boost pressure when driving.

The other day, I took a look and noticed my EWG was missing a bolt, and put one in which should fix it. I went for a test drive, and the EWG was opening again, although the car boosted to 21PSI sometimes, and ranged from 18PSI-21PSI mostly when at WOT, but the car seemed to run fine, and I didn't notice anything wrong with it, not sure if that variance in PSI is cause for concern, as I do remember the car boosting to 19PSI (target) almost perfectly every pull before these problems turned up.

After a few days of driving like this, and the car running fine, the car started overboosting again, although the EWG was opening now (this was at high elevation, about 45 mins after a successful spirited drive through the canyons). I drove the car carefully home, and the next day, it drove fine again, hitting 21PSI at most, but usually hanging around 19.5-20.

Today, the car was driving fine all day, I took a long drive up to my friends house, and went for a ride with him. After a hard pull or two, the car overboosted and hit fuel cut again.

I am not sure what is going on here, and would love to get to the bottom of it.

I have a parts list in my signature.

I have noticed that sometimes AFR gets stuck at 14.85 (02 sensor 1, bank 1 low voltage CEL shows up as well, and stuck afr sometimes jumps between 14.85 and 29.25), which I assume just means its going bad, or the wiring is corroded, and the AFR was stuck when this happened, (although I thought the car doesn't go off 02 sensor when at WOT).

I also have a cylinder 3 misfire sometimes (on cold start in the morning usually, but sometimes feel it when at WOT, usually when the AFR is stuck.) And last but not least, I have a fuel system too lean at idle CEL.

Last thing, since I got the car, it has always idled weird, idling completely fine at 900rpm for 5 seconds or so, then vibrating a bit and rpm surges to around 970 rpm, and after 5 seconds, idles fine again, on and off, always.

Any idea what's going on here? I assume a bad upstream o2 sensor and boost leak could cause all of this. Already ordered o2 sensor, and will check plugs and do a boost leak test.

Update: as of my most recent drive, AFR is being read, but when driving, the car stutters all the time, like it's losing power for a second every second, on and off power as I drive. AFR jumping between 10 and 17-18 when this is happening, and goes away when hitting 5+ PSI, normalizing to ~11.5 while building boost, EWG also does not open anymore, although I think the bolt may have just come out due to vibrations as it had no threadlocker.

Thank you for reading.

Full list of codes I am getting:

PCM: no description.

P0303: cylinder 3 misfire detected.

P2187: Fuel system too lean at idle.

P0131: 02 Sensor Circuit Low Voltage (Bank 1 Sensor 1)

P0234: Engine overboost condition.


I am happy to take the car out and datalog and send it over to you as well, as I know simply anecdotal stuff may not help.

I have not been observing WG duty or Fuel trims, but can if desired.

 

I think you have the right idea for the first round of checks. Report back what you find

Check the plumbing one the ewg and ebcs too

 

Logs, preferably ones safe for the engine. If you're having issues outside of boost, that should get some progress on this, at least. One step at a time.

Also what fuel are you running? If it's a mix of ethanol, and depending on your oil, you could be having issues with the HPFP spill valve (likely fixed with cleaning). Logs will show this though.

As far as the EWG bolt backing out, you may have some vibrational issues. My turbo tried to uninstall itself a while back (T25 flange, 4 studs) and after years of no issues at all, this (likely) happened after a spark plug shit the bed and went through the turbine, chingering it up good and probably unbalancing it slightly. Might need to double nut or lockwasher it or something.

 

Getting the o2 sensor in tomorrow and will replace and test tomorrow night. I'll update here, thank you!

 

What

 

If the o2 sensor replacement and boost leak test/repair doesn't work, I'll record logs and attach. (Checked LTFT and it's sitting around +15 when cruising, -0.6 when building boost).

I'm running 91, car is dramatuned but the shop is not in the same state as me.

I'm regards to the EWG bolt backing out, do you think threadlocker would do it? Or should I fix the underlying problem (and how would I go about figuring it out)?

 

*Heavy Russian accent*
Son of bitch.

Someone else can tell him, I'm getting tired of it.

As far as the bolt goes, I'd inspect for wheel damage (both hot and cold sides) before you try anything else. Threadlocker on an exhaust part is a bit of a tossup, so might need the old double nut or lock washer or something.

 

Sorry, don't know if I did something wrong or am missing something here.

I will try to double nut or get a lock washer.

 

https://mazdaspeeds.org/index.php?threads/dramatune-problems.2847/

 

Oh shit, thank you for the heads up...

Had no clue his tunes were causing problems. Anyone you would recommend for a retune? I live in Los Angeles, but am fine getting a remote tune done if Dyno is not possible here.

Looking like maybe an e-tune from freektune might be good?

 

I self tune so I'm not the best resource to ask, but I honestly have no problem with recommending Will (Purple Drank).

And yeah, I've seen multiple Drama cars blow up this year, at least one of those was a freshly built block.

If there's one thing I can guarantee its that whoever you get tuned with next will not only tell you if they see problems with the car, but also get you to a point where it runs better than you've ever had it running with Drama. Not talking power (that's a given), but just driveability in general.

Even if you're not done with your current tune you should just ghost his ass; the simple fact that you were overboosting and not hitting any safeties suggests that none were set up (or set up properly) in the first place. That's just how he rolls.

 

Will reach out to Will from PD, thank you for the info and the heads up, will definitely get a retune the second I get my current issues sorted. A small price to pay for more reliability (and power/useability).

 

I would recommend contacting him immediately for a basemap to run off of to sort your issues out. Rules out tune issues.

 

Why do people use dramatune

 

OP Both freektune and purple drank are both excellent tuners can't go wrong with either. I've been freektuned for 9 years now

 

I have noting but good things to say about Will@PD. He will take care of you for sure. He's very direct and to the point and if you just listen to what he's saying you'll be good.

When I started my tuning process he spent a good 15-20 mins on the phone with me tolerating/answering all my stupid questions.

 

Clearly this one didn't know any better.

I actually wonder if the basemap from his new tuner won't resolve a bunch of issues hes having and possibly be faster.

 

probably

 

Could fix a chunk, still has to do all the pre tuning checks, fresh plugs, boost leak test, fix that ewg, that in itself could solve some of it. I wouldn't be surprised if the MAF cal is off on the current map based on what we've unfortunately seen previously from Drama

 

Just replaced o2 sensor, car is running a little better, although misfire on 3 is still present at idle (checked plugs, all in good shape and gapped correctly), now I just have to fix EWG and do a boost leak test. Hoping a retune will fix the misfire.