Well it is an aftermarket cat, but I bought it at the muffler shop I went to. However I was told that aftermarket cats are usually not as good as oem and many have problems when it comes to smog. I'll have it replaced. How do I clean the o2 sensor? I mean is there anything special used to clean it or do you just wipe the carbon deposits off? Thanx

 

depending on the heat range of the plugs too you wont see carbon deposites of them cause when they heat up it cleans them off, but yea staying on topic i have a full exhaust and i see black smoke after letting of the gas at higher RPM thats not a bad thing right, BTW i agree with zedron tgfns

 

^^ You're running rich. I don't have that problem anymore. Now they say its the cat . What plugs do you guys recommend I should run??

 

stock ngk v-power plugs. iridium suck balls and waste of money. Same with the platinum crap.

 

i dont know if this will help u or not but..... a buddy of mine did a trick to get his mazda 626 to pass. Here it goes.. he emptied his washer fluid bottle and put water in it and put a vacuum hose down into in and connected it to the intake vacuum line. I've never tried this but apparently it worked wonders. Try at your own dicretion ok.

 

Sounds like something like seafoam. What this would do is break up carbon deposits on valves and such... I don't think I have a problem with this since the head was fully rebuilt and now it only has 900 miles on it... There should not be abundant carbon buildup

 

but it would also be cooling the engine reducing noX quite a bit.

 

So the engine was sucking up water into the intake manifold and therefore into the combustin chamber? Hmm, sounds risky, because what if it sucks up too much?