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.

 

The front O2 sensor is possible, but doubtful. Is the check engine lamp on
now? If so, have the code read or a diagnosis done. This code will be the
largest hint to the cause of the issue.

 

The front O2 sensor is possible, but doubtful. Is the check engine lamp on
now? If so, have the code read or a diagnosis done. This code will be the
largest hint to the cause of the issue.

 

The front O2 sensor is possible, but doubtful. Is the check engine lamp on
now? If so, have the code read or a diagnosis done. This code will be the
largest hint to the cause of the issue.