This morning I installed a set of NGK BP8ES plugs. After instalation I started her up and let her warm after approx. one minute I noticed my AVCR boost controller was turning off and on. I drove the car into my garage and checked all the bc's wiring and quick connects. Everything looked normal, so I moved to the ECU conections, and again it all seemed fine. I started the car again and it was still doing it. So, I decided to pull the plugs and recheck the gaps, connections, etc. (this was the only thing changed sinc the previous night when she was acting perfect)

After inspection of the plugs ( they all checked out ). I reinstalled them and started her back up. Everything seemed to be back to normal. Then I cleaned everything up and put all my tools away, went to start her up and again same problem. So at this point I am like WTF , and decide to pull the plugs again and put the old ones back in. The only difference between the two sets is that the old ones were NGK BPR8ES and the new ones were the BP8ES. Got everything switched up and started her. No problem. let her warm up completely and reved it a couple of times (I even hit the two step to build some boost) . It seems to be back to normal.

So the only thing I can think of is that the new plugs were not firing properly and making the ECU think that the engine was off and then back on and then back off very quickly, causing the AVCR to trip out.

Any thoughts, cause this one has me baffled?

 

Leave the 7,s in. You will get absolutely no difference in performance or how your plugs will burn with the mods you have. I went through this with my 03 8. I didnt have any cells come on or anything, I just wanted to see if there was a difference in the 2 heat ranges. After running both plugs for a week at time the performance felt the same and the plugs were burning beautifully. Both of them. So just leave the 7,s.