Toyota Repair: sensor problems, toyota camry v6, o2 sensors

Question
Hi,

I have a '94 toyota camry v6 and back in oct. 2011, my engine light came on. The code that i got was p402 EGR valve....i changed it in Nov.2011. Now, my light is on again...this time, i'm getting code p0125 (insufficiant coolant temp. close loop). I'n not getting good gas mileage and accelaration is low. What's your advice?

-should i replace all or one of the following: thermostat? ECT sensor? O2 sensors (3 in my car). To note, i replaced O2 sensors back in 2002...how long they're good for?...and i never change thermostat or ECT sensors. So, please help...trying to save a buck! Thanks!

Answer
This is actually an indication of bad O2 sensors, on this engine either one or both in the exhaust manifolds can cause this code, replace both sensors in front of the car converter and use factory OEM if possible, try not to use the one's from autozone etc they may only last a year or two maybe. Use the Denso brand sensors they are also available from non dealer sources online and in some autop parts stores, they are the same as Toyota uses, they just put them in their trademark boxes.