Failed Smog - 92 Civic DX - High HC, CO, and Super High NOx

[AaronMartinSole]

Originally Posted by Rusty94cx

Yes it's always cheaper to diagnosis than throw parts at it. I commend you for getting compression and vacuum readings. They tell you so much. Cats don't fail there is always some problem that makes them fail. Glad you passed. Seafoam is also goo for decarboning I used to use castles fireball stuff. Man.

Actually I reacted prematurely. Haven't taken another smog test yet, and my car is still smoking during warm-up at least. I've done compression and vacuum testing and they were good.

I think I have a better idea and a few new details. I think that it wasn't the water, just it was just the car warming up. I think the car smokes when cold, and after it warms up to operating temperature, it stops smoking, but high RPM's are necessary. I think if I let the car cool back down, or start it up again tomorrow morning, it's going to smoke. There could be many reasons for this and I'm reading up on it around the internet. I would call it 'smoke on cold start'. Might be normal. I doubt I failed those smog tests because the car wasn't properly warmed up, because even if it wasn't properly warmed up, I don't think it could give 3000+ NOx without something being wrong. But I don't know.

Read one guy had a car that smoked a lot. He cleaned out a few vacuum lines and blew some carb cleaner and compressed air through the EGR line. He said it didn't smoke after that. Maybe I should check and clean my vacuum lines, maybe it's coolant, who knows. Would burnt coolant cause a smog fail and how would it affect HC, CO, and NOx readings. Whew boy, but at least I'm getting somewhere, and can at least make the car stop smoking, if only temporarily.

Also my oil seems watery. Maybe the water injection had something to do with it, or maybe it's been accumulating since I changed the oil, I don't know. Probably the water treatment because I think that might've happened to someone else too.

Car is probably running rich or lean. Maybe a sensor is defective and giving the wrong readings. That's the direction I'm going in for now.

I might change my head gasket. Maybe it is a coolant leak. I've never done that before and that should be fun. But I am reading a lot of reports that in cold weather, it can be normal while the car is warming up. Eh... who knows. The car does stop smoking after it warms up, and doesn't smoke all the time, so that's really good. I guess I could test my head gasket further.

[some_other_dave]

Use your nose. What does the smoke smell like? NOTE: Don't do this too much, because carbon monoxide is in the exhaust and can kill you if you breathe much of it.

If the smoke smells sweet (you may be able to put your hand in the smoke and then smell it to avoid inhaling much CO) then you are burning coolant. That's a very significant problem.

If the oil seems thin, examine it. Water or coolant in it will separate out, because oil floats on water. Take a sniff of the oil. If it smells like gasoline, your oil has been diluted with gas, probably from running too rich or from plugs not firing or some such. Oil that is full of gasoline doesn't lubricate very well, so it should be changed if it smells a lot of gasoline.

-soD

[AaronMartinSole]

Got a Magnaflow carb legal CAT: 36304 - universal for about $140 shipped.

Just passed today about an hour ago with flying colors!



Mechanic had an odd way of testing the cat, apparently it's Honda's procedure to have the car crank for 15 seconds, with the fuel working and dumping loads of gas into the cylinders (I saw 30,000 ppm I think of HC), quickly taking off the distributor cap, and then jumping some lead to the little spring inside there. Something like that. And I think the CO2 or something was supposed to be at a certain level and it was not. Catalytic converter condemned. Of course, it's so much better and easier with OBDII and mode 6 and stuff like that. Kind of crude and crass and old school, but it gets the job done.

Man, the tailpipe smells so fresh now. I feel like hooking up an oxygen mask up to that thing! It's like breathing a soft green meadow! (just kidding. don't anyone do this. you will fall asleep and you will die.)

Man, when I passed I was exuberant and in shock. Didn't want to get my hopes up. And I didn't even barely pass, I passed with flying colors. Man, it feels good. I like catalytic converters. I love everything about them. I love smog repair. I love being able to breathe outside. I like seeing the numbers improve on those sheets. I wonder about performance driven motoring enthusiasts. Why modify your car to add horsepower if you don't run it on the dyno and know how much more horsepower you're actually getting? For instance, I read somewhere where they performed tests and a straight pipe adds so so little horsepower, I think it was around 1 or 2%, over a catalytic converter. I love fuel economy, but I wouldn't enjoy it half as much if I didn't know my real numbers, and see real improvements. But anyway, I am really happy and really pleased. Smogging is one rollercoaster of an experience, from anguish to hopelessness to anger to suspense, to absolute surprise and joy. Makes it all worthwhile. Feels good.

[California98Civic]

Great news. Thanks for the report back.