What type plugs have you tried ? I have the IK-22 and now have a miss after 11K. I am going to go with the with IK-20,s or the double platluim.. Just dont want to keep paying $600 for a plug change...

 

I have only tried the ik22 and the factory plugs. After reading dozens of posts on the subject, I think the best bet is the Bosch OEM plug. RFR6DPP332 Cheap and the same as the Beru factory plug.

 

Sounds like reset cleared everything. Wait and see kinda situation...

 

Looks like the problem has returned as bad as ever. I don't think the reset will help this time as it is happening all the time under load.

Looks like it is back to the shop. I will get them to check the MAF.

 

A lot of folks claim that the one step colder plugs are better. Early last year I spent a few days calling a few pros and aggregating as much info/research as I could - conclusion: if you're in the 600-700 bhp range, go with OEM plugs. There's no evidence by any tuner (at least the three that I talked to) that claimed the others outperformed the OEM ones or vice versa. They have preferences - but there is no statistical evidence either way.

If some one does have controlled tests/results - I'd be interested, out of simple curiosity.

Personally, I've stuck with OEM's and all is good 12k in... and I'm no slouch on the pedal either.

BTW: my issues originated from faulty (stuck) turbo actuators, ate my plugs withing a few hundred miles, as well as some other issues due to raised backpreasure.

 

I would agree with that assessment of plugs. And as my mods are similar to yours, i would agree that i fall into that category.

It is booked in for Monday, so my list of areas to check are now as follows: FPR, MAF and now the actuators.

 

We ran stock oem plugs on high 800whp cars for years with no issue.

 

Did you pressure test your car yet?
Headers looks fine?

 

No i have not. The headers only went on 100 miles ago, so unlikely to have contributed.

 

I vote for a bad coil... I had a bad one and it caused very similar symptoms as you describe. One day I got so miffed at the hesitation, I just floored it when it hesitated - then it finally threw a code and told me what cylinder was misfiring. I changed the coil on that cylinder only and everything was beautiful from them on. I had lived with it for 4 months.

 

My car was in the shop today getting , oil change, double exhaust tips and plugs. My mechanic showed me how one of my coil,s had a small crack in it. So since he was in there I replaced them all. Car will be done tomorrow, Looking forward to it. Keep in mind the only miss I had was at high boost. The ik22 plugs looked bad with worn out electrodes.... 11k on them..

 

Unfortunately last time the misfire followed the plug when things were swapped.

 

Did you happen to inspect the coils packs for cracks ?

 

Further development, but still not resolved.

The car is running lean. The MAFs have returned incorrect voltage, so they need to be replaced.

Get this. They wont warrant the MAFs due to the BMC filter. WTF! I have ordered some Bosch replacement units for less than have the price.

They better replace the plugs they installed after false diagnosis or I will be completely p!$$ed.

 

Flash it with stock file then scan it. New codes may appear!