O2 sensor and Trailing coil failure(Rtek 2.1).Urgent Tuning Tomorrow!
 

Ok,I started the car,running in Diagnose mode and it started fine,\Then it shows 02 Sensor..still runnig ok,then all of a sudden,Meow!..it shoots off a trailing coil failure and runs like shit.
so far,I changed the leading,trailing,Cas,Spark plug wires and the Plugs themselves.
This all happens as soon as I get a Guy that is willing to Tune the car,,and he is gonna be here Tomorrow!
any Ideas?..I am gonna run a wire to the ecu via the wideband(was running stock ecu wires to the Stock o2) and then cleaning grounds on the trailing coil brackets,,first thing in the morning.
Any Ideas would be appreciated.
Thanks Guys,STYX.

you checked the wire themselves from the coils to the ecu to see if there is a short or too much resistance?
is there 12 volts going to the two black/yellow wire to the trailing coil?

I finally, was able to trace down this root of this problem.
It was related to TOO Much oil in the gas(premix) and it would foul the Plugs.Trailings would not fire.
It only took a 2400 dollar ECU replacement to really know this,and a tuner who knew WTF was happening!..
anyways,I posted this so it may help others if they encounter this same scenario.
Cheers STYX!~

how much is TOO much oil? I target about 100:1 in my s5 t2 FB3S.... what you running?
-Chris

I am now using 100ml per 20 litres..and a shot for good luck.(it is one of those Chain saw Mini bottles.)
Before I was putting in about 1 oz per gallon..But I was measuring off the side of the bottle,so it could have always been MORE.
That was my problem,NO consistency.