Spark plugs

[stiorbust]

On my 08 sti I have 55k on the clock. I ran the engine for sev yrs without s tune running an.injen intake. We were having issues during a current tune with the map. I and others believe the plug may be damaged from running lean. First pull 256whp but after that less than 200. When I pull the plugs how will I tell if they are damaged. I will be pitting.ngk one step colder plugs in. Thanks
Grant Sampson via tap a talk

 

[ZachTTLM]

Grant running lean they would have a white look to them. You would also want to see if there is heat stress on the porecalin (sp), I do recommend upgraded plugs, however if it was not firing properly normally you would get a misfire code and such.

 

[Vermont]

Grant running lean they would have a white look to them. You would also want to see if there is heat stress on the porecalin (sp), I do recommend upgraded plugs, however if it was not firing properly normally you would get a misfire code and such.

Unfortunately not always with the gr sti's. Me and holy ran into a very nasty miss fire problem caused by the cam shaft sensor. We even trued a WOT run and the car miss fired so bad it felt like I had hit a brick wall with all the shuttering and jerking around. Not a single code was thrown. We even reached 80 some odd counts of misfires on one cylinder from it. Even so I am not so sure that a blow plug would be the cause of that issue. Then again you alot more miles than me and I not as well versed in spark plug lore as I should be...next time you are in for your tune have the runner log miss fire count on all four cylinders. This will isolate which one is the problem.

 

[stiorbust]

I pulled all plugs which wasn't bad. The gaps on avg were. 35 and factory gap is. 30 hmmmn I'm gonna install the ngk one step colder later.

Grant Sampson via tap a talk

 

[Vermont]

If you still have a miss fire after you swap plugs, I would try swapping the coil packs around and see if the miss fire follows. If not try injectors... eventually we will find what it is..

 

[stiorbust]

Enough to have caused the air fuel maps to go nuts above 4k on the dyno during my tune?

Grant Sampson via tap a talk

 

[Vermont]

Enough to have caused the air fuel maps to go nuts above 4k on the dyno during my tune?

Grant Sampson via tap a talk

Yes.... When you are miss firing everything is going all out of wack.... As soon as you ran into this problem your tuner should have did another pull while logging miss fire count per cylinder for all 4 of them.... this will tell you where it is coming from and will help to diagnosis the problem. For instance if you only had a miss fire on cylinder number 2 then you can rule out a faulty fuel pump and a few other things. But if it is across the board with a crap load of miss fires seemingly at random then you can rule out injectors, coil packs and spark plugs...

 

[stiorbust]

I know Jordan. I'm the one who thought of it. He still doesn't think that's the issue. I.just installed them. Fingers crossed

Grant Sampson via tap a talk

 

[stiorbust]

Now the o2 sensor that would have been prior to the cat is bad. I had driven the car.about 30 miles after pitting the new plugs in. During that the cel came on. So frustrated. Wanna give up

Grant Sampson via tap a talk

 

[IGOTASTi]

Now the o2 sensor that would have been prior to the cat is bad. I had driven the car.about 30 miles after pitting the new plugs in. During that the cel came on. So frustrated. Wanna give up

Grant Sampson via tap a talk

Don't give up!

 

[Vermont]

Now the o2 sensor that would have been prior to the cat is bad. I had driven the car.about 30 miles after pitting the new plugs in. During that the cel came on. So frustrated. Wanna give up

Grant Sampson via tap a talk

Owch that one is the expensive o2 sensor... you are look at around $170-$200 for a new one. I busted my front O2 sensor as well whiling installing an up-pipe.... I sprayed it with wd-40 to try and break it loose and the wd-40 ended up toasting the sensor.... Before you buy A new one though you might wanna check that the wire didn't get cut or disconnected... the wire runs up the passenger side of the block and meets up with the connector right next to the passenger side strut tower and is very prone to being messed with while you are working on that area. You may have accidently pulled/frayed the wire while installed the spark plugs.... just food for thought...

 

[stiorbust]

Ok so I will have the precat o2 sensor Monday from subie and the cobb ap came today. Thank good for great friends and a helpful father cause I was ready to give up. My tuner wants to verify with the cobb that the o2 sensor is faulty but.unknown by the hesitation that it is. Grr please end this madness soon but we made some good steps. Anyone have an idea what map to run. Should I reinstall the injen intake and remove the oem? I appreciate all the support. I work full time, full time nursing school and two kids under five and we are moving so you guys rock!

Grant Sampson via tap a talk

 

[stiorbust]

That sounds good. Ill take it

Grant Sampson via tap a talk