Emissions Testing

[EquatorHeat00]

Will a partially blown headgasket cause me to fail emissions next October. My exhaust tips get black right away even after I just cleaned them (real black). Also, what about a rattling stock catalytic converter will that be bad enough to fail me? (I believe a piece of the honeycomb inside on the front part is broken off inside, and trapped in there because the rear honeycomb is still all intact my guess for the rattle.)

[ConElite]

The Blown head gasket I believe will make you fail the Sniff test. The rattle might be the O2 Sensors.

[EquatorHeat00]

The rattling is coming from inside the converter.

[ConElite]

The rattling is coming from inside the converter.

You sure. Does it do it at idle? Turn on the engine and with a rag apply pressure on the part the wires come out of the Sensor. There are like these caps that come loose.

[Injuneer]

What coolant are you running? Conventional (green) coolant contains silicone compounds (Dex-Cool does not). The silicone compounds contaminate the O2 sensors and destroy them. A cat with a failed substrate will rattle. Eventually, pieces of the honeycomb will be blowing out the exhaust system. Sounds like you have both problems. Either is enough to cause you to fail a tailpipe emissions check.

[EquatorHeat00]

So if I replace the O2 sensors, and cat right before emissions testing I should pass even with a partially blown headgasket? (Yes, the car definitely rattles at idle thats when its most noticeable.)

[Joshu]

Well first you gotta tell us what kinda coolant you are using. And I don't really think your car will last til October with a partially blown head gasket. Do yourself a favor and fix it before you engine becomes junk.

I accidently (first time ever filling a car with coolant way back) filled my car with the green stuff that Fred above was talking about when there was already the orange coolant (Dexcool) in there. My head gasket blew two months later. The coolant system was way clogged from this and took three flushes. Three months after that I found myself replacing the O2 sensors.

Short Version: Fix the headgasket and replace the O2 sensors (if neccesary)

[EquatorHeat00]

Had blown head gasket since august, and thought if O2 sensors were bad car would drive rough which it doesn't. Car drives good. I use green coolant its a 94. Until I notice a thickening of the oil which I havn't I'm not concerned about it. (I was told like a chocolate milkshake.) Now answer my previous question??????????? In change oil now every 1,500 miles instead of 5,000 since problem - oil is runny not thick.

[Jeffs Black 97 Formula A4]

Not to go off-topic, but what if I'm using the new coolant that is supposed to be better than Dexcool? I had my radiator flushed last summer at an express lube and I specified Dexcool to them. When I saw them topping off the coolant I asked if it's Dexcool they're using, they say "no, this is better than Dexcool, does not cause corrosion like Dexcool does".

Anyway, my car seems OK so far, but will I have problems down the road because of this coolant? Thanks

[Injuneer]

How could anyone answer that question, when you don't have the slightest idea what they put in there? Generally not a good idea to accept the word of a $5/HR oil changer, particularly when he was not providing the services you specified.