EGR Valve

Has anyone here disabled the EGR valve on their 1KZ-TE either by blocking the ports off or simply blocking the vacuum line to the EGR diaphragm, hence stopping the exhaust gas recirculating to the inlet manifold.
If so, have there been any issues i.e. increase in temperature/overheating, irregular running etc.
Other forums indicate a increase in power and better mpg when disabling this although my main concern is possible head overheating and any issues with the EFI timing.

Heres a bit of info I found on EGR (exhaust gas recirculation)
The EGR reduces NOx (nitrogen) emissions, NOx is created at high combustion temperatures that occur under heavy load. To lower combustion temps you introduce exhaust gas into the intake charge, this replaces some of the O2 (oxygen) with inert exhaust gas, so you get less bang, lower temps and less NOx levels, and as a side effect smoke under load. So shutting it off naturally increases power, increases combustion temps and increases NOx emissions.

dunno about reducing inlet temps i read somewhere that this could have been a contributing factor of the 2lte heads cracking but had mine a few years and not had any probs.try fitting an intercooler to reduce inlet temps will help with power also

The role of the EGR in gas and diesel engines varies greatly. I think what Dwayne has quoted applies to gasoline engines.

From what I understand, in a diesel, EGR occurs mainly during idle and is reduced as the RPM's increase. I doubt one would notice any difference in engine efficiency unless you spend a lot of time idling.

Please correct me if I am wrong though.

I think you may be right zoochy. I was having a look at a KZN130 (Hilux) ECU pinout chart, 1KZTE motor, and the EGR control applies 9-14V to the EGR VSV while idling. This voltage will actuate the VSV (solenoid) allowing vacuum to be applied to the EGR diaphragm, opening the valve and allowing exhaust gases in.
The control says 0~3V with engine warmed up and >1500rpm and this would be the closed state on the VSV i.e EGR valve closed.
Interesting. Assuming of course this ECU function applies to our Customs.

Update: I have tested the vacuum line to the EGR diaphragm and can confirm that vacuum is on during idle i.e. valve is open and exhaust gas is entering inlet manifold.
As you increase the revs the vacuum switches off as described above with regard to the ECU control.