Car MY00 with full decat. I am getting hesitation (with occational misfire) prior or just as boost comes in after a quick 10 minute or so blast or after coming off the motorway. So in other words when operating temperatures are hot.

All other times car drives perfect. Have cleaned boost solenoid, unplugged MAF when idling to check ok and am running AE800 ECU so not afflicted by the original 802.

Could it be the lambda sensor that is failing at high operating temps?

Any other suggestions most welcome

Cheers

Martin

 

Spark plugs over heating/breaking down?..when was the last time they were replaced?
Have had a couple of cars in recently that have needed plugs due to similar circumstances...

 

Spark plugs?

Beat me to it LOL

 

Thanks for very quick replies guys

Had thought of plugs, but were changed 20k ago and on MY 00 aren't they NGKPFR6's with a supposed life of 50K? Should I stop being a tight sod and just buy some new ones anyway?

Would you go for 6's or the cooler 7's? read somewhere that 7's only last 10k!

thanks in advance

Martin

 

Lasting 10000 is not to do with them being 7s as no one to my knowledge is fouling them on a Subaru Turbo. It is more to do with people pushing their engines ever harder. At 350-400 BHP the 7s may have a life of about 10000 miles true enough.

20000 miles is quite a long time IMHO, when I only had a decat and a remap I could feel my original PFR6Bs going off after about 15000 miles.

I would get some PFR7B in there gapped to 0.7mm, good condition spark plugs are important for engine performance and longevity. It is an easy thing to rule out and new plugs after 20000 won't do any harm at all.

 

Many thanks for taking the time to reply John.

Your advise will be acted upon poste haste as I believe you have a bit of experience with the MY00

Cheers

Martin

 

LOL

Agree what John has said about spark plug life...20000 is too long on a turbo car (IMHO),i recommend changing them every 10000 regardless...and only NGK 7's

 

Thanks for the advise. 7's on order