Not sure how much info to give and still stay brief.
99 Sonata 2.4 4cyl
Bought about 1 year ago. Had check engine light: Code was for bank 1 lean.
Car ran fine. Reset light - stayed out for a day or two.
Several months later performance began deteriorating until car choked out and died
eventually replaced catalytic converter; much improved but some hesitation
hesitation continues especailly when cold; when was car has trouble upshifting
and is especially unresponsive around 2000 rpm
If I floor is it will shift but when I let speed/rpm drop to 2000 or so it wants to bog down.
Someone has suggested O2 sensors.
HELP!!!!
Thanks in advance.