Slugish 2000 i30-Need thoughtshttp://www.nicoclub.com/forums/thread-icons/confus

[i30guy]

Hi Guy!I have a sluggish, likes to knock, i30. There are no check engine lights on. The coil over plugs are new. I note that there is a slight hesitation when the engine is cold, but this resolves in about 2 minutes.

I have replaced 2 of the 4 O2 sensors. I have a new knock sensor, but I cannot find it ! I took off the air box. I can't find it any where. Anyone know where it is ? It is not in the same spot as say a 96 Maxima.

Do I need to have the ECM flashed with the new o2 sensors.

Thanks in advance!Brit

[MattB]

Check the MAF sensor. That sluggish behavior when cold can be a sign that it has failed. It's a relatively common problem on this model.

[loystock]

Below is the link to the FSM that shows the KS location (pages EC-20 and 338)

http://www.nicoclub.com/FSM/i30/2001/ec.pdf

A failing KS will trigger a fault code but will not turn on the CEL. A faulty MAF sensor will will trigger a fault code and turn on the CEL. However, a dirty MAF sensing element or poor connection may or may not trigger a fault code but can give all sort of problems. So Matt is right. Better clean the MAF sensor and connector. Use a zero-residue Contact Cleaner (or CRC MAF Sensor Cleaner) but DO NOT TOUCH the MAF sensing element. Apply dielectric grease after cleaning the connectors.