P0135 - Do I need a new ecu?

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now its a 91
I am working on a 2004 civic dx with the d17A1 engine. The car was giving me 2 codes, 2770 and 135. 2770 was an easy wire fix; but I can't locate the problem to fix 135(heater circuit malfunction primary o2 sensor).I have replaced the ground wire from the sensor to the ecu because there was a short in it and I have tried a Bosch and a Denso sensor thinking this was the problem but I still get code 135. I have a manual from ALLDATAdiy.com :: Leading Source of Diagnostic and Repair Information and have followed the troubleshooting flow chart and everything checks out good. The ecu controls the ground circuit and that is why I think the ecu needs replaced, what about you?
In case anyone cares, the problem was someone had changed the engine harness to a previous model year and it was set up for a narrow band but the computer was looking for a wide-band. I just had to change/add some wires in the right spots.
Can someone tell me if a 2004 civic dx with a d17a1 has an egr valve? Long story short I changed the computer in the process of finding out about the wiring and now I am getting an egr code (P0404). My manual is telling me that only the d17a2 has an egr, did the wrecking yard give me a wrong ecu? or did someone "do away" with the egr? I had the transmission go out too, replaced it with a synchrotech transmission though.