cat overheat light help needed

[obiwanwasabe]

Hiya,
I have just aquired a neglected '91 yellow beat and fitted a replacement engine, the old one smoked a bit! now the cat thermal sensor light was on when I got the car and is still on all the time with the new engine, I don't know if this is relevent and cannot find any info but the Co reading is 0.02% at idle and the engine seems to lack power, it revs fine to the redline but on taking my foot off the pedal and giving it light throttle it is very jerky and feels to misfire slightly, and doesn't drive smoothly at lower revs, timing is set at 20 at 1200rpm with the service connector bridged, I believe the sensor for the cat is shot and Honda want £200 and wait a month for delivery from Japan for a new sensor, does anyone know what the resistance is for this sensor and if it can be bypassed? could this sensor be affecting the performance of the engine?
the gasses out of the cat are all within tolerance to show the cat is ok.
help needed please.
Nick

[tinytim]

I'm pretty sure all the sensor does is operate the warning light (no signal to the ECU) but I'm sure Steve can clarify that when passing . You can short the socket to earth to stop the light comming on or remove the bulb.
On a known good but not new sensor I can't get a definate reading but it fluctuates between 50ish and the low 100ds in Ohms. If your light is on all the time and your sensor is not O/C it's gonna be a broken wire/fuse

[obiwanwasabe]

Cheers for the reply, I had come to that conclusion, just needed it verifying that it did not affect anything on the ecm, I can now look further into why it is so jerky, it just feels to be running too lean! I have bridged the service connecter and all is ok with no blip codes from the mil light, so just have to check whether the strobe I used to do the timing was accurate or not (it was an old one, may buy a new one as it looks like it might get some use!)as the idle seems to be about 1500 and not too steady..

nick