Spark plugs gone wrong (help)
 

So my car has downpipe, full sri 3” Corksport, hpfp, and tuned ots from cobb stage 2
I changed my spark plugs to ngk 6510 1 step colder and i noticed that my car is now underboost and my launch is slower now, you know that feeling, it doesn’t break my neck anymore. And i have no idea what’s happening. If u guys know what’s up with my car please tell me.

Are the plugs gapped properly?

Make sure that you didn't cause a boost leak during the install.

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Im newbie with gaping, i prolly gapped it wrong. What’s the best gap?

Hello this might be the cause of it cuz after installing it i had a rough startup but then after like 10 sec it went back to normal. I test drove it and everything seems fine. But after that i noticed that my boost is not going all they way up its like limited or something and then checked if there boost leak and then i saw the clamp hose between the intercooler and throttle body was loose.

And it is still underboost idk why I can’t feel the power i felt before i changed my spark plugs.

The Mazda service manual as revised in 2010 states that the spark plugs should be gapped to between 0.024" and 0.027".

if the car start fine and idle ok but gap limit power, it would be under the form of very noticeable misfire...

it is more likely a leak but if you ran the car with it and even if you solved it, it will take a while to learn the changes if you didn't reset the ecu. (loading your map again or disconnected battery and drain remaining voltage.... )
If you aren't sure of the solved leak, you may ask a mechanic.

Agree and disagree with these;
Disagree - If your car is running poorly because of a leak and you fix it you will know right away. What the car "learns" will have little effect on hitting boost targets. I hear this "learning" missinformation all the time.

Fully agree - You should definately ask a mechanic as you had trouble gapping plugs correctly and even messed up reinstalling things you just took off. Maybe mechanical stuff just isn't your thing.

it cost 0$ to reset the ecu in that kind of case but i agree with you that it will run better with the leak solved....
But you need to agree, It will run even better once the LTFT/STFT will be stabilized again with the new readings...

I'm just not perfectly sure that LTFT/STFT affect maf cal to get load or just maf cal for AFR...if it affect load and you have a tune with some load control remaining to control boost, your wastegate duty and boost will be affected. I could be wrong but it cost nothing to try.

I gapped the plugs to 0.027” but im still getting underboost i still can’t feel the power

Take a datalog and post it, also post an earlier one from when your car felt faster (in the same gear) if you have it.

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datalog49 is where i had the old spark plugs
datalog52 is after

I think you need to re-do the After log starting at about 2750 rpm.

Do you have the proper MAF calibration for the CS 3" intake?

Car looks weak on the before log. Only peak 12 psi?

Less boost than before and very rich AFR in the after log so you probably have a leak.

Your two logs show entirely different running conditions. In the first log, you actually took a proper WOT log from 2700rpm-ish to around 6000rpm. In the second log, you only went WOT at around 5500rpm.

You cannot draw, nor expect us to draw any conclusions from the data you've given us. If anything, the portions of the datalogs that do overlap indicate broadly similar operating results given the differences between the boost air temperatures.

You should also make sure to log accelerator pedal position in your logs to make sure that the accelerator pedal position and throttle position track each other properly.

You might want to look a bit more carefully. The AFR actually looks quite similar in the same portions of the rev range log-for-log. I'm not convinced there's a leak since it's still hitting 11.32:1 at 5500-ish and tapering down to the 10s as revs rise.

However, @tegxsi; is 100% correct. You do not appear to be running a map that is safe for the modifications on your car. If you have a 3" intake, you need to be using a map that is calibrated for the increased diameter of that intake. The 3" intake is about 28% larger than the OEM intake. The car can only accommodate about a 15% difference before reaching the limits of its internally-adjustable calibration.

Furthermore, the COBB OTS maps are pretty much garbage. You really need a custom tune for the modifications on your car.

In the meantime, check all your hose clamps and make sure you don't have any leaks.

The "before" doesn't look too bad other than the under boost. MAF cal is a mystery but the AFRs look ok.

The "after" log is a mess to look at. I just focused in the areas where the throttle plate is over 76%. Peak boost is ~9psi and the AFR is in the low to mid 10s.

You're correct. I only hurriedly looked over the "after" log. I didn't notice that there was a second WOT portion around lines 500 - 594. The AFRs are way rich in the second log, and that definitely indicates a boost leak.

If AFR = then i just need a proper tune?
Thank you guys ill post another log in about an hour

Well, I've been waiting for an hour and twenty minutes. I'm calling it a night. :yawn:
:yawn:
:yawn:

sorry guys got busy i had some unexpected company.

If the car was running fine why change to colder plugs. Seems the guys that needed them years back when running big boost and advanced timing with e85 or meth to stop blow out every man and there dog thought they should get some to for shitty OTS maps etc.

With ageing engines and blow by etc cold plugs can be a bad choice as they can foul up with oil.
I'd check the clamps on the intercooler hoses since i'm guessing it's a top mount that was taken off to change plugs.

It’s prolly cuz of the plugs
Every hose are clamped tight properly
But i will be getting tune from freektune, and hope that fix my underboost problem.

Yeah, your AFRs look much more like they did in the first log and seem to be reasonably well controlled. As a result, I'd say that your car is running normally and that, as usual, Cobb's maps suck donkey balls.

Several issues you need to take care of here.

1. You're running a 3 inch intake which is not supported by any of the COBB OTS maps. It says right on the Corksport page that you need a custom MAF recalibration. Your MAF cal is way off, I'm surprised your car ran fine before the plug change. You need to buy either an OTS tune designed for your intake or a custom tune.

2. The plugs you selected come with a huge gap out of the box and are a poor choice for 1 step colder. Those plugs come gapped at 0.044 which is way too wide even for stock power levels. Gapping them down to 0.024-0.028 which is where they need to be is too much bend to run reliably.

3. If you want 1 step colder plugs, you need Denso ITV22 which come gapped 0.032 and then reduce the gap to 0.024-0.028. Much less bend required.

Update on my car. I saw a fresh oil on the ground under my car.
Cause of it = unnoticeable misfire? = spark plugs? Or loosed bolts?
I’ll prolly just save this spark plug until i get a higher boost tune.
What’s the best alternative oem spark plug for Mazdaspeed 3 2011?

are you blaming spark plugs for oil underneath ???

I ran NKG 6510 one step colder plugs (see mod list in my signature) exclusively for ten years gapped down to .026” with no problems whatsoever with 3” catless dp/rp and an 18-19 psi tune tapering to 15 psi at redline with a lot of timing advance (about 18 degrees at redline) and very rich AFR for cylinder cooling, getting 300-310 whp maxing out the K04 on pump 93. They never fouled. Had the opposite problem with wear, having to replace them between 15,000-200,000 miles. I ran them to help against detonation because of the boost and timing.

Not saying they are needed by OP, but whatever the problems he is having with low boost, it ain’t the damned plugs. They are iridium tipped and easily damaged if he scraped the fine wire tip when regapping. The ground strap is plenty capable of gapping down from .044” to .026”.

The oil is not because of your misfire, and certainly not because of your spark plugs. I don't know how you could even think that at all.

Not sure cuz my dodge neon had misfire problems and my oil starts leaking

Ill check tomorrow and see what’s the problem.
Ill try changing my plugs and see if anything changes

Agreed likely not a plug issue and not saying the 6510's don't work on this platform, but in his case it seemed like the ITV22 was a better choice than those NGK's considering he didn't know about plug gaps.

Either ITV22 or stock heat range correct plugs would have worked out of the box if he didn't gap them at all with his current mods and tune. 6510's required gapping immediately or wouldn't run right out of the box.

Denso IV22s developed a bad reputation here for multiple instances of broken insulators falling into the cylinder heads of our engines. There are several threads here with photos. Most guys now run NGK plugs, either stock or one step colder.

Yes, the NGK 6510 one step colder plugs must be regapped. They would misfire like a MOFO otherwise. They were intended for another OEM application. Always check gap on new plugs, anyway, even stock. Gap is often not correct.

The 6510 should work fine with his mods which include both an aftermarket downpipe and 3” intake, once he gets his crappy tune sorted out and a proper maf cal for the bigger maf housing intake.

Be very careful gapping them. Do not use a coin type gapper, as it will scrape the iridium plating off of the fine wire tip. Use a common lever type gapping tool with wire feeler gauges available at any auto parts store. Be sure it goes down small enough.

Like this one, which is in millimeters on one side and inches on the other:

https://images-na.ssl-images-amazon....aL._SY879_.jpg

To narrow the gap, tap the ground strap on a block of wood. To open the gap use the tool extension on the side to grip the strap like a lever and gently bend it outward. Do not get it close to the center insulator.

Sorry but neither your neon or mazda will leak oil because of misfire unless it break a rod and make a hole into the bloc to spill oil....
If you believe this, you should stop working on your cars and let mechanic do it for you.

You can have a valve cover gasket going bad and leak around the plugs but it isn't related to misfire at all.

-Update
it wasn't the motor oil. it was the freaking power steer and it is leaking for some reason
not sure why.
u guys are right oil leaks are non related to misfire or anything.
And my underboost problem was because of the that grabage ots tune from cobb.
definitely would get a custom asap before the winter comes.
-another update for my spark plugs
not sure if ngk 6510 is causing 6+ kr and base on my research that is not good.
bought another ngk that's pre-gapped to 0.027" after the test run i didn't get more
than 4+ kr.
I think my problem is solved now, but i have to figure it out why my power steering is
leaking.
Thank you everyone for your time looking into my logs and helping me.
I know I may not be a great mechanic but the best part about this is learning
from my mistakes.

for kr you need to look at it only under boost condition in a log....instant peak kr on the AP is meaningless...Some is even created on purpose by the ecu to find the best timing under cruising condition for fuel economy....
If you have 4-6 degree under boost it is another story that worth to figure it out

What he said ^^

At low throttle applications, under cruising conditions, and so forth, the ECU increases ignition timing until the engine begins to knock. Once knock is detected, the ECU decreases the ignition timing until the knock disappears, and then starts increasing the ignition timing again.

This is done to improve fuel economy under light-load conditions.

It is not uncommon to see very high knock retard values at low throttle. The only knock that matters to you is the knock that happens under high throttle, high load conditions.

In any case, you'll need to datalog to see where and when your car is generating knock.

I'm really curious what these datalogs will show actually.

6+ under what conditions? What number “other NGK” plug? Not advocating one step colder, but the purpose of colder plugs is to reduce the likelihood of KR at high boost high timing advance, at the possible expense of fouling under less aggressive driving, so less KR with normal heat range plugs seems odd.

As others have said, you will get KR when cruising. Look for KR conditions when running wide open throttle and if present, seek to get them under control.