Trouble with oxygen sensor in Hyundai right after changing the timing belt.?

Right after having my timing belt changed in my 2001 Hyundai Elantra, the check engine light came on. A diagnostic says that it is the Oxygen sensor 2 in bank 1.





It seems wierd to me that this code would come on right after the timing belt was changed. I suspect that my mechanic likely did something wrong that made that code flip. Is it possible that he got the timing off just a little bit that brings less oxygen in? Could he have disconnected the sensor when changing the belt? Or could it just be a coincidence that the sensor went bad when my mechanic changed the timing belt?





My mechanic says he did nothing wrong and wants to charge me to change the oxygen sensor. What do you think the problem is with the car? What should I do?|||im not sure if the o2 needs to be disconnected to remove the timming belt covers. if he%26#039;s so sure he didn%26#039;t cause the problem i would assume he probably knows that he didn%26#039;t ever disconnect it. have you looked to see if it is disconnected? sensor 2 is the one behind the catalytic converter..it%26#039;s only job is to make sure the catalyst is working. you didn%26#039;t say anything about it running roughly so i would think the valve timing is how it%26#039;s sopposed to be. if the timing was off you would have position sensor codes or maybe misfires.





wasn%26#039;t there more to the code then just %26quot;sensor 2 bank 1?%26quot; how many miles are on the car? o2 sensors do go bad sometime|||Well, likely intake cam is off 1 tooth. Unless he forgot to plug it back in. You could let him change the OX sensor with the understanding that if doesn%26#039;t work he will replace it with your old one,no charge. Should be able to do this while you wait.|||try and reset the computor by undoing the positive side cable of the battery and hooking it back up this will erase and reset codes but more than likely your timing is off a hair you probably have 2 O2 sensors one the ex, manifold and the other down by the catalist converter