Is this normal? I went from a very good tune to a lean tune (could be something else, as tune is very good) just by switching from standard AC/Delco single wire to Denso 3 wire. My engine now goes into closed loop after 32 seconds, and the fuel is showing LEAN, very lean all of a sudden. When I drive it it is popping through the exhaust till it warms up to about 180 degrees water temp.
There are no vacuum leaks, plugs are new NGK TR55, DELTEQ ignition, LT1 with XE 230/236 Comp Cams. No header leaks, everthing mechanical is SAT.
Any advice would be appreciated.
I can email a TTS file too, if you want to look at it.
PS, I ahve already emailed a couple of guys that know there stuff, but for yuz guys.
Checks made
Headers: Good, no leaks
Valvetrain, Good all valves adjusted
Plugs-New
Wires-Good no arcing or burnt wires and they are on the plugs.
O2 Sensors- Working Good and tight in header
IAC-Working and steady (Never really had an issue with it)
TPS- .67 volts or very close to it at idle
Even changed chips from original to 2 refined chip, and no obvious change

 

ttt ??

 

I suggest you take this to the PCM diagnostics and tuning section. They'll probably be able to help you.