Maybe someone here can help with my problem so I don't have to start a new thread
I just installed the HFC, didn't change anything else.
Fired the car up, started smooth, drove it around for a while, drove nice, then took it back home.
Later that evening after the turbo area cooled down, I went back to install the extender for the O2 sensor. Fired the car up and oh my god it runs like ****. It lurches and chugs like an old carborated engine for the first 40 seconds or so while the engine is warming up. The whole body of the car shakes and it feels like the engine is twisting. Then eventually, the RPMs jump to about 1500 and it smooths out, slowly lowering over time to a regular idle.
No codes get set immediately
I take it for a drive. It feels like the O2 sensor is shot. Inconsistent acceleration, surging at steady speeds (rpms sometime dropping by 500, or about 25%) before coming back up. Just all around bad performance, too many times where my stomach dropped because I thought it was gonna throw me into limp mode. Eventually I get a code - P0133, Bank1 O2 sensor response slow
The o2 sensor is old, so I order a brand new one. I was thinking I might have broken a wire in the old sensor putting it on since with the extender the butt of the plug sits right up against the firewall and I can barely fit it in. So I carefully install the new one, clear the codes and start the car.
Same problem. Car feels like it's trying to twist itself into a pretzel when it starts, but the surging on the highway isn't AS bad, only dropping between 20 and 100 rpms.
Frustrated, I take the extender off. Put the o2 sensor back on, and... It runs fine again. But of course without the extender I get the code for the cat.
Anyone have any clue what I'm doing wrong?