dc2 with k20 problem

[Aaron1259]

I finally got around to replacing my Primary o2 sensor, drove it for around a month with the cel light on, and I think it was just running rich, black smoke on high revs and sounds like it was missing a cylinder in 2nd around > 2.5 - 3k otherwise it ran ok. However after replacing it the cel went away, but the car feels like its running really rough, it will idle around 1200 then drop to around 500 - 800 then come back up. while its cold and I put the clutch it the car will sometimes drop to 0 and stall, and if it doesn't and i've come to a stop its will almost drop 100 a few times before coming to its odd idle. And driving around 100 down the motorway it feels as if something is pulling the car back every few seconds, feels like the car is rocking back and forth.

I'm thinking it needs a tune, and yes I did reset kpro after installing the new sensor. Any ideas into what's happening?

[Adrian @ SAS]

I'm thinking it needs a tune

Probably figure most of it out on the dyno...
Could any number of things....dirty/blocked IACV, plugs, dirty injectors, the tune you have.
Hard to say sight unseen.

[Aaron1259]

Just started it this morning after driving it down the road and the cel came on again, got home and check it, p0134 Air/Fuel Ratio (A/F) Sensor (Sensor 1) No Activity Detected, has brand new iridium denso's. I inboxed you about a tune.

[Adrian @ SAS]

Just started it this morning after driving it down the road and the cel came on again, got home and check it, p0134 Air/Fuel Ratio (A/F) Sensor (Sensor 1) No Activity Detected, has brand new iridium denso's. I inboxed you about a tune.

Check the heater circuit relay for function then back probe sensor to ECU for continuity / circuit check.
If OK, problem is base code in tune mismatched to ECU type