camery 99 stall at slow down

my Camry 99 was having high and low rpm problem i went to mechanic he
checked and replaced map sensor fixed the problem but car still stall and
shut down on stop sign or slow down and restart after a minute later.
Mechanic check, IDE,sensor,clean throttle,checked battery ,evr and hoses
etc and could,n't find out the problem.he asked me to take second advice. he
said he doesn't want to replace anything expensive if not required eg: fuel
pump. this is the only source of my income.my car temp stay in between  low  
middle.i afraid of starting heat also. i had to drive 35 mile every day and it
run smooth on the highway but. i cannot afford money to dealer but please
advise i will appreciate thanks.