YACT: 1990 Honda Civic failed emissions test expecting the worst

[alm99]

Anyone have an idea what the average cost to replace the catalytic converter is, if need be?

 

[flot]

I wouldn't count on the problem being the cat itself, unless you have a reason to suspect it.

AFAIK, the average price of a replacement cat is somewhere around $90-150. (if you have to get a honda specific one made for the car, I'd imagine it'd be a bit more) Then a few bucks to have someone remove the old one and weld the new one in.

 

[alm99]

Well I was assuming the most expensive piece would be the cat, but there isn't a funky smell like it had gone bad or anything

 

[flot]

The cat is just a metal box with a brick of catalyst inside. That's probably the cheapest thing that could "go wrong" which of course is why it's the least likely. In fact, even if the cat were to turn out bad - that's just a sign that something else is wrong. (Catalytic converters shouldn't really "wear out" if your engine is running properly... at least, not that I've ever heard, and certainly not in a 1990 car)

If you are just trying to pass emissions and you're in a bind for $, I'd go one of two routes.

1) Find a shady emissions place that will magically pass your car if you slip the guy $50
2) Look into some of the fuel additives that claim to help you pass emissions

I don't live in an area that checks, but I have heard anectdotally that both #1 and #2 work with remarkable success.

 

[alm99]

According to the emissions test, the NO2 levels were too high

 

[Kipper]

Were the other levels of your emissions high? If so, it may be the cat, but if not look somewhere else, like the exhaust gas recirculation, etc.

 

[alm99]

Originally posted by: MadCowDisease
Were the other levels of your emissions high? If so, it may be the cat, but if not look somewhere else, like the exhaust gas recirculation, etc.

other levels were way below the maximum level

 

[Zenmervolt]

Extremely high levels for oxides of nitrogen (NOX or NO2) tend to indicate higher than normal combustion chamber temperatures. Double check that your car's radiator and coolant are up to par (you have been changing the coolant every 2 years, right?) and that everything else is functioning properly in the cooling system. Also, running lean can cause higher combustion chamber temps, so double-check for vacuum leaks in the FI system and run a bottle of Techron through the tank to make sure that the injectors are firing cleanly.

Outside of that, if you're mechanically-inclined you can retard the timing just for the test and re-set it when you're done. This will adversely affect the other emmissions, but if you have headroom to play with them it's something you could try.

ZV

 

[thomsbrain]

at least in CA, they check the timing as part of the emissions test.

 

[Shawn]

I paid $130 for a highflow replacement for my car. I put it on myself though.......

 

[Kelvrick]

When I had to pass smog, ended up the only thing wrong was a tube that popped off of the egr.

Also had high nox.

 

[TechnoKid]

the EGR valve is waaaaay more expensive than the cat converter. though i'm not sure if the '90 civics had egr systems...


OEM cat converter is about $475 from slhondaparts

 

[alm99]

interesting, thanks for all the suggestions. The radiator is a bit corroded and could be the source of the problem.

 

[Thegonagle]

Originally posted by: flot
The cat is just a metal box with a brick of catalyst inside. That's probably the cheapest thing that could "go wrong" which of course is why it's the least likely. In fact, even if the cat were to turn out bad - that's just a sign that something else is wrong. (Catalytic converters shouldn't really "wear out" if your engine is running properly... at least, not that I've ever heard, and certainly not in a 1990 car)

If you are just trying to pass emissions and you're in a bind for $, I'd go one of two routes.

1) Find a shady emissions place that will magically pass your car if you slip the guy $50
2) Look into some of the fuel additives that claim to help you pass emissions

I don't live in an area that checks, but I have heard anectdotally that both #1 and #2 work with remarkable success.

First, take off your EGR valve, check for obvious mechanical failure, and then clean it with carb cleaner. (The '90 Civic has an EGR, the '92-95 doesn't.) Then ghetto-test the EGR valve off the car by attaching a hose to it, and sucking HARD. (Sorry, sickos!) You should be able to see it open up, and it shouldn't leak. When the engine is warm, and the engine speed is above idle, you should be able to feel vacuum at the hose that connects to the EGR valve. If not, there might be a problem with the vacuum control solenoid that feeds the EGR valve, or with the electrical circuit that controls the vacuum solenoid. If the EGR system passes your quick tests, the system is probably functioning fine.

Second, magical cheater fuel additive = alcohol. Two-three little bottles of "ISO-Heet" 99% isopropyl alcohol added to 1/4 tank of gas can help you pass. If you can find pure ethanol (grain alcohol), that will also work. Methaonl (denatured alcohol, wood alcohol) can also work, but it's very bad for the fuel system, and I don't recommend it.

On second thought, if it's available in your area, just add a half-gallon to 3/4 gallon of E-85 (85/15 blend of ethanol/gasoline) to a 1/4 tank of gasoline.

Edited for more suckiness!

 

[Thegonagle]

Bump for edited post above.

 

[alm99]

Originally posted by: Thegonagle

Originally posted by: flot
The cat is just a metal box with a brick of catalyst inside. That's probably the cheapest thing that could "go wrong" which of course is why it's the least likely. In fact, even if the cat were to turn out bad - that's just a sign that something else is wrong. (Catalytic converters shouldn't really "wear out" if your engine is running properly... at least, not that I've ever heard, and certainly not in a 1990 car)

If you are just trying to pass emissions and you're in a bind for $, I'd go one of two routes.

1) Find a shady emissions place that will magically pass your car if you slip the guy $50
2) Look into some of the fuel additives that claim to help you pass emissions

I don't live in an area that checks, but I have heard anectdotally that both #1 and #2 work with remarkable success.

First, take off your EGR valve, check for obvious mechanical failure, and then clean it with carb cleaner. (The '90 Civic has an EGR, the '92-95 doesn't.) Then ghetto-test the EGR valve off the car by attaching a hose to it, and sucking HARD. (Sorry, sickos!) You should be able to see it open up, and it shouldn't leak. When the engine is warm, and the engine speed is above idle, you should be able to feel vacuum at the hose that connects to the EGR valve. If not, there might be a problem with the vacuum control solenoid that feeds the EGR valve, or with the electrical circuit that controls the vacuum solenoid. If the EGR system passes your quick tests, the system is probably functioning fine.

Second, magical cheater fuel additive = alcohol. Two-three little bottles of "ISO-Heet" 99% isopropyl alcohol added to 1/4 tank of gas can help you pass. If you can find pure ethanol (grain alcohol), that will also work. Methaonl (denatured alcohol, wood alcohol) can also work, but it's very bad for the fuel system, and I don't recommend it.

On second thought, if it's available in your area, just add a half-gallon to 3/4 gallon of E-85 (85/15 blend of ethanol/gasoline) to a 1/4 tank of gasoline.

Edited for more suckiness!

Say I find the EGR valve is bad, is it just a simple swap with a new one or is there more involved. My haynes manual says to take it to a mechanic for checking, but doesn't mention replacing.