I was getting a code 41(O2 heater) I bought a new O2. That fixed it for about a day. Then my car hesitated in low rpms and threw a code 43. It seems to be running rich. Any ideas? Its a '93 Ex stock P28 with header.
The only thing I can think of is exhaust leak or the O2 wires could be switched?

 

my buddy had the same problem so we switch out the 02 sensor and the code came back teh next day and what the real problem was that he had a crack in his headers right in front of the cat got it welded up and the problem went away

 

Ya that's what I thought. My jeep had a cracked manifold but it was really noticable.

 

Code 43 may indicate a problem with the O2 sensor circuit, so check the O2 connector and wires carefully. Another potential cause for code 43 is a fuel system problem, for example with the fuel pump, filter, injectors, or pressure regulator.