my winter beater failed emission...help!

[ak]

Hey guys, My beater failed emission badly here in IL. Here's the detail...hopefully someone can give me an idea of what's wrong.

I have a 88 Mazda MX6 turbo with the following mods:
intake/2.5exhaust no muffler with dynomax highflow cat(2yrs old)
Superchip
turbo upgrade

Now my emission result was
HC=1.87(standard=0.8)
CO=29.2(Standard=15)

Possible causes are:
1. I have not driven this car for the last month...literally!
2. Superchip too rich?
3. O2 sensor...?
4. Sparkplugs are 2 years old...due or replacement? Wires are about one year old.
5. Cat is bad?

I know HC is due to the mixture being too rich. I am thinking this is the superchip doing it but could it also be O2 sensor? What causes CO to be so high!? HELP!

 

[lemansnsx]

Originally posted by ak:
I know HC is due to the mixture being too rich. I am thinking this is the superchip doing it but could it also be O2 sensor? What causes CO to be so high!? HELP!

You definitely need to change the plugs and I'd go ahead and change the air filter, pcv valve, etc. You don't say the mileage but, if the O2 is original I'd change it - but you should be seeing a trouble code if it has failed. Be warned - they can be a real pain to change!!! Also check that your EGR valve is functional - check that the thermostat is operating properly 'cause the EGR solenoid is usually connected to it. Proper EGR function is critical for NOX. Products like "Guaranteed to Pass" are worth a try - follow the instructions and forget about trying to claim on the "guarantee" part - you'd have to jump through hoops to get your refund. Timing correct? Is it easy to put the stock chip back? (Sorry, I don't know Mazda computers)


------------------
Andrew Henderson
The NSX Model List Page

"We have long acknowledged that enthusiasm for things automotive is a sure
sign of emotional instability if not outright dementia" - Brock Yates

 

[nsxxtreme]

I have found that the product produced by STP called smoke helps with reducing emissions. Cut my emissions in half on my beater. You probably have different issues than I had but as a last resort what the hell.

 

[nsxtasy]

One other thing not mentioned yet. On most cars (not just the NSX), you need to get the engine REALLY HOT to minimize emissions. If the testing facility is close to your house, take the car for a long ride on the way, and keep it in as low a gear as possible. If you're waiting in line, keep the motor running at high revs (in neutral, of course).

 

[ak]

Hi guys. Thanks for the input. I already put the product that claims to pass emission. Also put the stock chip back in. I kept the engine very hot when I went to test but no luck. I'll try to drive highway to get max effect today out of the additive. My O2 sensor is 2 years old and don't get engine check light so I'm assuming it's ok. Will try to clean the EGR valve also. wish me luck....i'm going back tomorrow.

 

[lemansnsx]

With the stuff that goes in the tank you did follow the instructions to drive through that whole tank and refill before going for the test, right? You most likely won't pass with that stuff still in the system.

------------------
Andrew Henderson
The NSX Model List Page

"We have long acknowledged that enthusiasm for things automotive is a sure
sign of emotional instability if not outright dementia" - Brock Yates

 

[ak]

It said that I'd pass with 3/4 tank left... Maybe I misread it?!

 

[lemansnsx]

Originally posted by ak:
It said that I'd pass with 3/4 tank left... Maybe I misread it?!

The stuff that I have used says to do as I described and the CRC web site agrees.


------------------
Andrew Henderson
The NSX Model List Page

"We have long acknowledged that enthusiasm for things automotive is a sure
sign of emotional instability if not outright dementia" - Brock Yates

 

[ak]

Well I passed...sorta. I cheated a little by putting on my 17" wheels so they couldn't do dyno test. My idle test result was very clean. HC was like 22(standard=220) and CO was 0. I think i'd have passed with dyno test too but I couldn't risk it as I'm in the middle of moving and don't have time to deal with this. My EGR valve was stuck closed so that probably had something to do with the failure. I feel bad as I am all for clean air and all. Maybe it's time for me to get the hybrid civic for a daily driver! ULEV and 50 miles/gallon! anyway, thanks guys for your help.

-ak

btw the stuff I used said go test after 3/4 tank is used up.