2000 Camry LE 4cyl stall
 

Hi everyone, I'm new to this list but hoping to find some guidance.
We purchased a pre owned 2000 camry le 4cy for my son as a reliable and safe car. Our 1998 is still going !!
Our issue is that it keeps stalling out!
Any ideas or help would be appreciated
We've been dealing with this between our own mechanic and dealership repair and I'm afraid we'll have to return this car due to the safety hazard we are having if I can't find an answer
Here are the particulars:
Runs great, starts great no issues...
Mechanic checked car with nothing major being a problem before we purchased it. but... on it's first big drive 60mph for min 30min.. while coming to a stop on a deceleration it stalled.. started right up again.. did it a second time and then only once did it stall at a stop light. each time tach goes up and down between 0-1500 seeming like it can't find it's idle once it's been running for some time. Each time it starts right up and doesn't do it again until "whenever"
-took to dealer, they found no codes since the check engine light didn't come on so they checked and replaced the air intake resonator
-again same deal, stall within 5 min after a long trip 55mph+ for 30min + (no rhyme or reason with and w/o cruise control) this time though it did stall a second time about 20 min after the 1st stall but it was again on the deceleration at a stop sign.
-back to dealer, this time we cleaned the throttle body which includes the aiv and egr valve.
-Again same thing happened coming off the turnpike but this time it was on a quick decell due to traffic on the off ramp not a stop light and my son almost got rear ended, no codes thrown. Starts right up no revving of engine it just seems like it can't find it's idle. Did not have the problem on the same ride back home
- Finally took the car to my personal mechanic for an idea of what was up. He has 30yrs of experience and has never steered me wrong. Without hesitation after making sure there was no major engine issue and looking at what they did that he felt that cleaning the Air intake valve/motor was not enough it needed to be replaced. Bad EGR's only happen in extreme cases and if it was cleaned it was more than likely the AIV (his tech term was that sometimes after getting used so much they get "sticky or lazy"
It could be a number of other things (bad throttle plate, or throttle body position sensor, clogged fuel inj, bad fuel pressure reg, Torque converter clutch.) but he doubts any of those.. he said it's a classic thing to happen and the symptoms of what it does and doesn't do match it..
-so I call the service again.. this time I'm told they are sure that is not what it is, they never see a problem with them, it's usually the EGR... and of course still not sure that is what it is..
I asked if both should be replaced.. but because we are talking about them footing the bill they need to get back to me since they aren't sure this will fix the issue

So my questions:
Anyone else have this issue?
What resolved it?
Any other ideas of what it could be?
I trust my mechanic 100% but shouldn't toyota service know the make model better?

It's a nice car otherwise LOL but I'm inclined to take it back because
1. it's unsafe for my son to drive
2. now that I have had it to service and they are telling me it will be hit or miss and it's on the cars service records I'll never be able to sell it (nor would I in good faith)

any feedback would be appreciated.. we paid top price for this car, dealer has a good rep.. no ones fault really but honestly I paid for a car that was safe, reliable and ran.

Thanks
Markenplus2

update: of course since I posted this service called back. they want the car for a few days since they think it's an egr issue.. they want to recreate the stalling while driving and then feel to see if the egr valve is open .. sounds dangerous to me seeing as how you need to be in a good deal of traffic.. but at least they are trying.. no car for several days but they are not telling me to go pound sand.. I'd still like some feedback though because if they can't recreate this I don't think I want to wait for it to happen again

1. clean EGR
2. clean throttle body pintle valve and bore.
3. check idle speed valve. if it has, like Honda's, coolant lines to it, it needs to be cleaned. as in taken apart and cleaned.

How to Fix a Car That Stalls: 7 steps - wikiHow
How to Determine Why a Car Stalls at Intersections - wikiHow, the free how-to guide
Diagnostic flowchart for a car that won't start or stalls - Troubleshooting for the starter, spark failure and the fuel pump

When does the stalling occur (details are important)? Steady state speeds such as hwy, urban, etc. Acceleration or foot off gas pedal.

It is one thing for the engine to stall when driving at hwy speeds and RPM is steady. Another when the gas pedal is released, another if car is sitting at idle, another if it stalls when the gas pedal pushed.