Hey,

Just got these out of my car and put in some new NGK PFR7B plugs gapped to 6.6mm in (recommended by mapper).

I instantly noticed the poor state of the previous plugs after they were taken out (see image below). I'm assuming that this would have probably have made the ECU a little unhappy, so is it worth resetting it now that the new fresh ones are in?

By the way, can anyone answer why only two of the plugs seem like they're well used?

 

Not the best picture to be honest mate.They all look the same from that angle

 

I see, I was only really concerned about the ware, there doesn't seem to be any carbon deposits etc. If you see the plugs on the far left and right, there's significant ware, compared to the two in the middle that don't seem that bad.

 

Where's the electrodes gone on the plugs at either end, or is it the way the pics been taken

 

Nope, that's the thing, there's no electrodes on them.. I was assuming they've worn down.

 

does the car feel better m8?
thinking bout getting some ngk plugs for my wrx 2003

 

You can see the electrodes have worn/been sparked away. the inner two have pips of inner electrode left.
It's called spark erosion.

 

Thanks alcazar, would you recommend I reset the ECU though? I assume the car might have adjusted the ignition timing due to the ware. It's been mapped by Bob Rawle to 329bhp..

Car doesn't feel that different G4rfo.

 

agh ok m8
cheers

 

Is nobody concerned by the fact that he has gapped the. Es plugs to 6.6mm as I'm aware they should be gapped to 0.6mm or there abouts. I'd imagine that's why the old one have worn so badly.

 

For those that don't realise these are Denso Iridium plugs with the small tip which the two outer ones seem to have lost

 

Hello Ian, thanks for your reply, I spoke to the man who mapped my car a few weeks ago who advised the type of plugs to buy, his response was: -

"the plugs should be NGK PFR7B gapped to 0,65/0,70 mm"

Unfortunately the car has actually done 62,000miles and although I've done 3 oil changes since I got the car at 45,000miles, I have never changed the spark plugs until today. The documentation for the history of the car indicates no changes to the plugs either, however, they are iridium and I have heard that they can last a long time, i.e. 60k.

 

I'm not questioning your changing of the plugs just concerned that you have gapped them to 6.6mm or was that a typo? If not they need recapping to the correct 0.6-0.7mm
Cheers Ian.

 

Sorry Ian, I believe that's a typo on my part.

 

Looking at that pic of the plug box, two tips seem to have worn away, or broken off.

 

Its not un common for denso plugs to loose there tips. I wouldnt use them at all ever personally. Not even in my lawn mower. I think you will find most mappers/specialist would always recommend ngk. Your pretty lucky the tip havent damaged the bores

 

NGK for me .......

 

This is what i have recently taken out of my car

Car was running like a bag of hammers!! NGKPFR7B's have gone back in and its running well again.

I did not adjust the pre-set gap on the plugs going in and everything is fine!