Civic Exhaust manifold?

Question

i recently bought a used exhaust manifold for a 96-98 civic cx hatchback because the previous one it had, had a crach on the manifold so it was letting air out, andi thought that was teh cause of the "engine light". so i installed the other used exhaust manifold without any cracks adn when i started up the car, 1st of all smoke started to come out, i dont know hwere but aruond the exhaust manifold. 2nd the "engine light" still came up and i scanned it with my ob2 and it still was the "o2 sensor malfunction". does anyone konw what could be the problem of the smoke coming out and the "engine light"?

Answer 1

if you got the gasket on right it's probably just burning off the grease that was on your hands that got on the manifold .

Answer 2

The above person states it probably correctly. The smoke is usually from a new gasket or antiseize compound that is put on the bolts.

The check engine light from the O2 sensor may be lit still from before. Honda engine control units store codes and it will take several cycles to turn back off. Look in the fuse box (one under hood) for a fuse called "ECU" Remove that fuse for 15 seconds and then relplace it.

If you can not find this fuse, unhook the battery for about 30 seconds and replace it. Restart the car and you're good to go...

...that is, assuming the manifold was the problem. You could also have a faulty catalytic convertor or one of the two oxygen sensors. If the light comes back on, I would recommend taking it to a repair place for diagnosing and repairing the problem. If you know what you're doing, you can fix it yourself by buying a new primary or secondary oxygen sensor and replacing whichever one is bad (again, if you know what you're doing) Chances of it being the catalytic convertor are less than the sensor but figuring out which of the three is the tricky part.

Answer 3

Exhaust leak may be because the exhaust gasket isn't sealed right...real smoke all of a sudden could be oil smudges on the manifold from you.

The O2 sensor reading means it isn't putting out the required voltage, and likely needs replacing. Then you may have to clear the memory for it to stay out.

Then again, if your fuel/air mixture is wrong, or it just isn't being burned right, the light will always come on, until you fix that problem first.

Answer 4

either the coating from the brand new manifold
Like on my headers, it happens!

So far as the light,...check that Cat and see if its bad (probaly is)

Usually a bad cat or bad gasket sets this 02 Sensor off all the time!!