it solved 99% of the drivability problems I`v have had with the VE As in:

Poor idle when hot or cold...
Cooling fans coming on when not needed
Idle doesnt "hunt" or fluctuate all the time
When using A/C no rough idle

I read alot of poor idleing problems on here and I think If one hasnt changed the Cylinder Head Temp sensor it may solve some problems.

 

you can solve more of the idle hunting and fluctuating by removing your IACV and really cleaning it out, along with new gaskets for the TB and IACV. I didn't take it apart, I just used a pipe cleaner and some TB cleaner to really get the gunk out of the spring and plunger area.

Did you happen to check your ECU codes before replacing the coolant temp sensor?

Mine did have a code for that problem.

I also mentioned the same stuff in a couple of threads. I am glad you changed the sensor. It takes < 5 minutes and costs $20.

 

Is Cylinder Head Temp sensor and coolant temp sensor same thing?? I think I might need to change mine. My rough idle hasnt gone away all the and I have done almost everything (cleaned IACV and TB, injector check, plug, cap/rotor, wires)
except change TB gaskets, as red92maxse pointed out now.

 

I just changed mine because I knew I was going to be taking everything off and they are just a few bucks. I think the coolant temp sensor and IACV were the cause of my problems. Mine idles like brand new now.

 

the IACV isn't hard to take off, you don't actually have to take off the TB in order to take off the IACV. up to you if you wanan clean both though. the spray method without taking the IACV doesn't work since the design of the IACV doesn't really permit any cleaner near the spring. so my advice is to take it off.. just 2 hoses, 1 air hose and 4 10mm bolts. good luck btw buy the gaskets for the IACV first before you do anything.. i learned the hard way. and now my car is down fro another few days.. but in the mean time.. its time for a new thermostat and temp sensor. =D

 

if you take out the idle adjustment screw, you can get the TB cleaner in to where a lot of the crap is. Up from the air hose, there are chambers that don't allow the cleaner up in there very well. It's still better to take it off and clean it thoroughly.

Maybe I have trouble in tight spaces, but it would have been pretty tough for me to take off the IACV withough removing the TB.

Yeah, it took like 3-4 days for my local dealer to get the TB and IACV gaskets.

Oh, and I learned that the JDM IACV is different from my USDM one. It must work the same, but it definitely is different on the inside and the outside.

 

Temp sensor resistance is VERY easy to measure. Changing a good sensor helps only salesman; swap only if bad.

Two sensors: one is used only for EGR:

 

Like I have said before, check the codes on the ECU. There is a code for a bad temp sensor.