Changed spark plugs and now runs very rough or not at all

[peteris350]

I changed the spark plugs on my 2010 is350 and after putting it back together it is giving P1277 and P127B with check engine light on. Traction control light comes on intermittently as well. When I looked up the codes i found some information saying it might be cylinder 1 or 3 which I took the park plugs out and rechecked and everything looks fine. I haven't taken the intake manifold off again to check the 3 plugs on the other side but i'm curious if anyone has had this problem before and what they did. Any help is appreciated i'm carless until I get this thing fixed 😛 

[McBrian]

Plugs not gapped correctly (do not trust pre-gapped claims) ?

Incorrect plugs (OEM only. There are no gains from "upgrades") ?

Coil and or injector harness(es) not plugged in to the right cylinders and or they are corroded (DeOxit contact cleaner should be on hand every time you take off a connector) ?

Poor sealing, reusing old gaskets, crimping a new one causing an air leak. ? (Highly probable with all of the stuff that has to come off...)

 

[peteris350]

I took that thing apart like 6 times but finally figured it out. It was a 6 way housing connector that lead into cylinder 2,4 and 6. Four of the wires didnt have continuity so i crimped the four bad ones and it runs better than before! 
Thanks for the advice! I learned a lot trying to figure out this issue

[McBrian]

Wow. Nice find.