Used Cars: Problem with starting, sensors, reply

Question
I have 2001 sienna roughly <70K miles on it, once in a while it would not hold the idle. If i release the gas pedal, engine would shut off. Would you help? also, how many sensor this one have. with this van has less than 70K miles on it. I had to replace 4 sensor so far and the last one cost almost $400.
Thanks for reply advance.


Answer
Well I could sit back and take a couple guesses, but that would not do any good.  Just trust me when I say this, it will be a lot cheaper in the long run to have somebody check it out that knows what they are doing.  That vehicle probably has about 100 sensors on it, and probably 20 of them could be affecting that problem.  If you have already replaced 4 sensors, I would question who is doing the work?  Toyotas are really, really good vehicles, and I would think it to be extremely uncommon to have already replaced 4 sensors, and there is still a problem.  Toyotas are pretty complicated, and it takes an above average technician to work on them and properly diagnose them.