Hi all, '07 Cobalt SS SC here. I went OTTP stage 2 in the summer; 2.8 w/ 60's and the Largest OTTP heat exchanger, no dual pass. Car ran fine all summer, about 2 months ago I have 2 conflicting issues...

the plugs w/ the kit are the 1 step colder copper plugs by NGK, the 7 somethings. Around October, I threw my first code, a p300 @ idle. Never checked the plugs, I've been busy starting a business and working a 2nd job... finally got around to checking the plugs a few weeks ago... BLACK. Kept throwing a p0300 and then once or twice with the p0300 I saw a p0171 as well, uh oh. Always threw the code @ idle though.

So... the plugs are black, which means they are getting fouled up. I regapped them high just to see what would happen, I was assuming a bigger gap would make a more powerful spark (yes I know about the blowout of the spark @ high boost, I high about 16 PSI tops in this cold weather) but the 2 things happening contradict one another.

If my plugs are fouling, I'm rich, OR the plugs are too cold for my setup and I can throw the stockers back in to raise the combustion temps to burn off the deposits, but that could be bad to raise the heat if I'm running lean w/ that damn p0171. So I'm at a loss...

Should I gap the plugs back down to .032 or .030 as I have read up on to see if that changes anything? I won't buy new plugs til I hear some opinions, since I have the stockers which are in good shape & these plugs, both of which I cleaned up using a spark plug sand blaster @ my old automotive school.

I think it's the gap right now, since these plugs are highly recommended by stage 2 people and OTTP as well... doesn't change the fact that issues arose as the weather changed. I'm putting a bad-mab header and zzp 3" catted dp w/ 2.5 exit on in the next few days, I assume I should go get retuned with new plugs once the exhaust is in? I want to do that, but I want to get rid of this issue 1st, and perhaps a tune is the only way. I don't have a wideband or interceptor to monitor AFRs either damnit... I assume the fouled plugs are just not firing properly @ stock NGK gap and my new .038 gap.

I plan on cleaning up the MAF sensor and checking the pcv tube an intake tubing and cleaning up the TB as well, then regapping the plugs lower and reset the PCM and then keep an eye on things.

What can I do with my stock or 1 step colder plugs right now to help obtain optimal combustion? I'm fine @ WOT and cruising, just this damn idle bullshit that is confusing... fouled plugs, but I'm lean?! and isn't idle AFR higher than cruising AFR due to low vacuum?!

Help, suggestions, anything useful to add or say please do so, I'm confused right about now...

 

you need a tune its realy rich if you have an aftermarket intake that would be your lean code get it tuned

 

I'd invest in a wideband and get re-tuned. Canned tunes and tuning without a wideband can only be so accurate..

 

alright then, i'll do that right after i drop $500 for snow tires, $1400 this month in bills and then there's christmas gifts... can't wait :/

exhaust goes on once this damn snow melts, then tires then a tune... i'd rather have my whip in one piece then on the sidde of the road with a sick tune lololol

 

setting the gap on the plugs isn't going to lean the tune out

 

true, and that's not what my intention was either, but I was throwing codes on the daily with a smaller gap, when I widened the gap to .038 it went away, almost. And if it's lean, why am I fouling plugs? shouldn't i be burning them?

I need a wideband, bad... any recommendations?

 

your running too rich, (too much fuel) that's why your plugs are black, it's not the spark plugs. You need to either send the pcm back to ottp and tell them to lean it out and explain your problem, or grab a wideband and get a custom tune.

 

WB:

https://www.cobaltss.net/forums/part...sensor-236358/

You are getting the P0300 proably because your too rich, that is why you have fouled plugs. Get a WB and get a real tune, custom.

When you went with a wider gap you had more spark, it can burn the fuel. Problem with the larger gap is that you might have spark blow out up top.

 

wow, excellent find sccobaltss. and thanks for all the advice fellas. so the tune is rich obviously... check engine light didn't pop up as much with larger gap, for now can i throw my stock plugs in with stock gap, the are a hotter plug and therefore they won't foul up my plugs so much?? for the time being at least...?

and u can get a lean code for the intake, even if you're misfiring from too much fuel? i thought the p0171 would be due to an actual lean condition that the o2 sensors calculated, but it can be from the MAF getting too much air, outside of its 'tables' or whatever the tune info is called... i was supposed to be tuned for this, i told them i had an intake. i knew i shoulda gotten the parts and then got tuned, damn mail order crap...

alright, so i get a wideband, this is the 1st time for me so i have a few ?'s... 1) should i get a tune, post cat? it's not as accurate so i read, but it's not whether 'yes u can' i'm asking, 'what's the best thing to do' and 2) if u have to put the wideband o2 pre cat, how to do so? add a bung to my brand new header for that o2... or can i replace my stock o2 with a wideband??

Basically... I want the wideband. I want the tune. I wanna do everything myself, save for the drive in to a shop and get tuned part.

 

Its a canned tune. My car compared to yours compared to someone in Canada are going to be different, fuel trim or AFR wise. That is why you get a custom tune with someone that logs you and tunes from the log.

Tune post cat? Not sure what you are trying to say.

WB needs to go before the cat with a seperate bung than the O2 sensor. Put it in the DP.

I thought I saw some WB's that have a WB signal wire and a Narrow band signal wire to mimic the stock narrow band and you just use the existing bung... but I may have dreamt it..

 

when i ordered the zzp catted dp, i ordered the 'o2 wideband bung' option, i assume they put the bung pre-cat. i haven't checked, still in the box at my parent's house. i just g2 get a wideband, although i may have to wait until after the winter... can't tune for performance and use it when there's snow and ice on the roads and i g2 some funds together.

in the meantime i will pop my stock plugs back in to get a hotter combustion to burn off the deposits, (speculating) so then i won't be fouling plugs. rich or not, fouling the plugs and throwing codes is my primary concern right now, the fine tuning can be done come spring. i'll gap the stockers a bit higher too, say .035 but not as crazy as my current .038.

things r lookin good cept that i just dropped $700 on snow/ice tires... curbed a rim last night @ 4am, was only going 12mph and the abs just laughed at me while my summer tires and i screamed for help. ******* black ice... thank god for painted polished lip rims! face is fine, and as for the lip, nothin a lil sandpaper and spray paint can't fix.

As for now i will work on keeping my plugs clean and happy for now and CEL free, the wideband is definately the next step. I eventually want a Interceptor gauge, i mean comon... clear codes & view a ton of info, and doesn't it also allow for AFR readings too? or should I get an Interceptor, and a seperate gauge w/ the sensor? which sensor s best?

I will start researching now, but any personal suggestions are appreciated, thanks all

 

My question is I've done the Hahn turbo swap and was wondering what gap i should run?

 

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