dropped in the motor(k20 type s) and now using a Type R ECU into an ek chasis with the hybrid racing PNP harness. the car starts up fine but has a surging idle. the only CEL is code 6 which is coolant temp. sensor. there are no vacuum leaks and it tends to stutter a little when revving. what can the problem be?

 

u might get alittle more help on k20a.org

 

yeah k20a.org is a good source of K information and support. Is the raditor fan coming on? I would ensure the cooling system is blead properly and reset the ecu and recheck. back probe the ECT and watch voltage after bleading has occured and watch sensors events.

 

you either have a huge amount of air in cooling system or a vacuum leak somewhere...

 

my H series did the same thing with the bouncing idle and it was the iacv but take care of the cel first make sure you dont have low coolant or air in the system check the wires if they are good take the sensor out and see if it has a bunch of corrosion and trash on it if so clean it and see what happens if all else fails replace the sensor i dont think the cts is very expensive also check for vacuum leaks

 

Just got my k20r installed, I have surging idle as well.

We cleaned the iacv, we bled the air from the coolant system and there are no vacuum leaks....

The only codes it's really throwing are secondary O2 sensor.. Which shouldn't matter. Were a little stumped.

Goin to the shop again this morning, like in a couple hours, so any prompt advice would be greatly appriciated.