My 91 Accord won't pass emissions here in Ontario, Canada.
I believe it is the catylalic converter.
Has anyone replaced such a critter.
I believe it is just four(4) bolts holding it in.
Please correct me if I'm wrong and suggest any procedures on this operation.

 

there is three nuts on each side of the cat. depending on how rusted they are you may need a torch to heat the nuts but if you are replacing it then you could just cut them off. also if the cat was the cause if bad emisions the second o2 sensor would have indicated a failur dy turning on the check engine lite. It probably isnt the cat the car could be running rich this could make it fail also.

 

well.. he is obd1 so i think he only has one sensor. it easy to remove the cat. all you ahve to do is unscrew the 3 bolts on the muffler end and take the 2 bols off the header end. i had a small pipe for my o2 sensor that i also removed so that the cat could just fall out easier. dont forget to disconnect the o2 sensor, i think its a bad idea to let it hang on the little pipe.

 

If your NOx emissions are high then you are right it is probably the CAT. How bad is it? I just finally passed my SMOG test yesterday and was having the same problem. Try retarding the timing to 13-BTDC from the stock 15. That is how I passed. At 15-BTDC my NOx was 948ppm and at 13 it went down to 787. Max here in CA is 799 this time so I barely made it. So if you are within about 150ppm retarding the timing should do the trick. It lowers the peak cylinder temperature which reduces NOx emissions. Hope this helps...

 

:chuckles:


sorry man ... it just sounds funny


h:

 

I'll try retarding the timing as well. All three values that Ontario checks, the readings where 3+ times greater.
There is a fuel additive here call Gaurenteed2Pass. It contains menthol and helped my Camaro pass so I'm gonna try that too.