35ppm- The maximum allowable concentration for continuous exposure for healthy adults in any 8 hour period as recommended by OSHA.

200ppm- Slight headache, fatigue, dizziness, nausea after 2-3 hours.

400ppm- Frontal headaches within 1-2 hours, life threatening after 3 hours.

800ppm- Dizziness, nausea and convulsions within 45 minutes. Unconciousness within 2 hours. Death within 2-3 hours.

 

The O2 housing donut to downpipe gasket is a high probability area for leaks. Even on stock Evo X's we have seen this many times. The inside of the heatshield can appear black from the leaking exhaust.

 

So I left it at the dealership overnight, and they checked it out this morning. They couldn't find anything wrong....inspected all hoses...checked emissions...checked all bolts and seals along the exhaust.

I'll have to do my home-brew tests again once the car is cold again, and see if I can still get a measurable reading.

And there's always other explanations for headaches...."new car" smell, rougher ride, vibrations, noise-level, shifting, etc....

I do feel a little better having taken it to the shop for a check. Their advice (since this is a safety issue)....if I'm still concerned, I should call Mitsubishi USA and talk to their customer service - and they will direct the dealership about what to do next.

 

You know, I would not count on MMA for providing much support. I called them on a potential fuel dilution problem (fuel in engine oil) and the individual I spoke to was completely clueless; said I, to, should talk to the dealership. In short, the left hand does not ... is doing.

Later, Ken

 

wow very interesting

 

I understand what you found and everything, but let me just throw this out there as well. When you first start the car the engine idle is around 2000 rpm's or so warming up. Also, if you use the defroster or have the vents on and the wind is blowing in the right direction, you can get the exhaust in your cabin. I smell it all the time in the morning while my car is warming up. I think it's just a combo of the above mentioned factors.

If you had a dealership check your exhaust I wouldn't be concerned.

 

Thanks all for being patient with me on this. After obsessing over CO levels for the past several days, I've been able to recreate the situation pretty reliably. But - I've also been able to get the 2006 Honda Pilot to generate CO levels too. I think the Honda Pilot just has lower readings because it has a lot more cubic feet of space in the vehicle...so the gases take longer to build-up.


Some mis-conceptions I had...

I thought that if I idled the car for about 20-30 seconds in the garage with the garage door open - I'd be fine. WRONG. In the Evolution, AND the Honda Pilot. 30 seconds of idling in the garage with the garage-door open can generate CO readings in the cabin of the car. The key is the outside temperature. When its warmer outside...high-30s to 50s....idling in the garage with the door open seems to be ok. But, now that outside temps have dropped into the 10s and 20s...just 30 seconds of idling will produced a peak CO reading of 25ppm in the Evolution. And 11ppm in the Honda Pilot So be extra careful in cold weather -- an open garage door does not guarantee safety from CO.

Also check this article for more on that....


Also - I thought that idling outside would insure that no CO enters the cabin. WRONG. I couldn't reproduce this in the Honda Pilot. But in the Evolution...on rare occasions - I was able to get CO readings in the cabin of 10-15ppm just by idling in the driveway. As "Thegame" said above, its a factor of many things. Temperature and wind-speed in particular.

I've also learned that there is a rear-ventilator duct behind the bumper in the EVO X. Under normal conditions, fresh air flows from front-to-back. And the Fans in the cabin produce a positive air pressure which expels air at the rear. I have a theory - but don't have devices accurate enough to prove it. That when the EVO is first started in cold weather and the HVAC fans are off or on low-speed under the AUTO fan setting...exhaust gas from the rear can enter the cabin through that rear vent. Just a theory....




So my safety tips of the day for any car during the first couple minutes of starting a cold-vehicle..

...don't idle in a garage for longer than a few seconds in freezing weather (even with the garage door open!).
...And don't idle for long periods outside in the cold when there's little or no wind.

I've proven to myself that CO can enter the cabin under both of those conditions.

The good news though -- my EVO is fine...

 

I know this has nothing to do with CM, but when I had my Evo 8 my wife always complained about nausea on the rare occasions she had to go with me in my car. I replaced the shocks and struts with Bilsteins off a MR and that softened it up enough to where she could tolerate it. But, the Evo X GSR is considerably softer stock, so it’s not a problem for her. My point is that maybe other factors are causing discomfort for your wife.