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Carbon monoxide poisoning?

There is no smell in my car but I’m breathing in something that flairs my lungs and make me feel light headed
there is no loud sound so no one thinks it’s a leak in the exhaust- what else could it be?
I need to fix it- what ever it is it’s bad.
Any ideas of other things it could be?

Make/model/year/miles/condition of your car?

1996 mazda… old…

Take it to a good mechanic and have them carefully go over the exhaust system. You’re describing an exaust leak, it sounds to me, and need to get it fixed. Any rust on your car?

Thank you. No rust but an oil leak.
(and no sound)

You could get a Carbon Monoxide detector with a battery backup and put it on the floorboard of your car. If it goes off, roll down a window all the way immediately. The CO detector can be plugged into your house when done, any house with gas heat should have one anyway.

You may not have a leak in your exhaust system, but if there is a break in the seal around your hatch, rear window or trunk, you can suck exhaust fumes back into the car. When you are driving down the road, you create a low pressure area behind your car. This creates a lower pressure inside the vehicle that can draw the fumes into your vehicle.

CO is heavier than air so it will settle down towards the floor. If you roll a window down, the CO should not rise above the height of the bottom of the opening.

Thank you- I’m hoping to get a detector today - but afraid to get in my car to go get it! Actually wondering if I should have it towed to mechanic. All this info is helpful Keith - thank you-
also though - if I drive w/ my windows down and my sun roof open- I’m still getting my lungs filled w/ something and light headed… ? Oil leak? But then I’d smell it no?

Actually CO is not heavier than O2, about the same as N2, so it doesn’t settle at all. You’re getting light headed with windows and sunroof open?

If you are getting lightheaded with the windows down, then it needs to be towed. The sunroof will draw air up from the bottom to the top so it would be counter productive to have it open.

texases is right, I guess I was thinking that CO and CO2 would both have the same weight. It will be difficult to expel from the cabin of your car. You could have outside air selected and turn your fan on high, but this is really too dangerous to mess with. As long as you have less air pressure in your vehicle than outside, it can draw in exhaust.

You can at least check all around your trunk lid, rear window and rear doors for damage to the seals. Remove your spare tire and look all around the spare tire well and the rest of the trunk for any openings. You may come across something simple that you can fix yourself. Check especially on the side where the tail pipe is.

If you don’t find anything, then get the exhaust system checked by a professional.

Close all the widows and other openings, run your heater blower on A/C or vent which will pressurize the cabin and prevent fumes from leaking in and see if your symptoms go away…

Thank you all. (yes- light headed w/ sunroof open and windows open- lungs irritated.
I will do all above- I’m taking it to mechanic today who will help me locate it.

This is not a situation you want to let slide.  It is very important.  Chances are good that it will be a fair to low cost.  But even if it is expensive, you need to get it resolved NOW.  Those gases are sneaky.

small chance it could be mold in the car somewhere, but that’d most likely have some kind of smell with it.

It’s not only imperative that you get your car checked and the source of the problem corrected, but it’s also imperative that you get to your doctor for a blood workup. Don’t leave any “stone unturned” in resolving this. Carbon monoxide poisoning is basically depriving your cells of oxygen, and you do not want to mess with this.

I have checked w/ a carbon monoxide tester - and it didn’t go off. I am still suspicious however. And wonder about getting some official testing done. The fire department?

The engine light is on and it says something about the EGR flow not working and my mechanic says the EGR valve is working. it also says something about (or he said) the Oxygen sensor?

But could it just be a hose? I was thinking about just changing all the filters- oil- air - fuel- for starts?

I thought about mold- or allergies but I get such a strong immediate reaction.

No one can “smell” anything so they don’t know how to go about fixing it.
Thank you all- and yes- blood work!

The exact code(s) would help greatly. The EGR system consists not only of the valve, but also of a solenoid to open the valve and a tube + orafice through which the inert exhaust gas gets drawn into the inflowing air. It’s possible that the solenoid is opening the valve (i.e. the “valve is workiing”) but the tuabe and/or orafice is clogged with carbon deposits. Exhaust goes there, so that does sometimes tend to clog up.

I’m very glad to hear that you checked for CO. There are pocket size sensors that will measure the amount in PPM (parts per million), but I have no idea how much they cost.

There are other sources of odd smells, such as a leaky in the heater core, that could also cause a headache. Have you been losing any coolant lately? Is there any sign of oil seeping through a valvecover gasket and onto an exhaust component? Have you lifted the hood and stuck your nose under there looking for a source?

Maybe you can find a shop in your area that did smog checks before OBD2 came out. They might still have the smog sniffer, it can find sources of CO.

I had a home detector detect CO in a car once, thats why I suggested it, but your levels may not be high enough yet.

There are sensors that can detect CO in parts per million that are used by the safety and maintenance departments at many factories for their confined space entry program. If you have connections, maybe you could borrow one, but they are pricy little things to buy.

A home CO alarm takes about a 30 minutes to respond, (otherwise every cigarette would be setting them off) you would need to have it in your car for that long to see if it responds. Your local fire dept or health dept may have an industrial CO detector they could use for a reliable check, if you ask them nicely they may check it for you. Like Keith says a mechanic with a smog tester might also be able to test for you. Don’t mess around, get this checked and fixed before you get hurt.

Make/model/year/miles/condition of your car?

I get that that’s the board mantra, but how is it helpful in this case?

Borrowed a car- went to the doctors- got a blood test - results next week but he put me on oxygen for 10 minutes.

Finally found the firemen at the station! They were very nice and helpful- put the tester inside my car. Right away it showed a very low oxygen level (-20) and no signs of CO. But after a few minutes he revved it and turned the air conditioning on. It showed low but increasing levels of CO and they guessed it's probably higher when I'm driving.
(They said it could also be a freon leak that would cause low oxygen.)

I appreciate all of you expressing concern and the importance of getting to the bottom of it!

So- trying to figure out next move.

I've already had the codes read- every time I go anywhere they want to charge me 100 - 125 just to read the codes..
My mechanic says it reads EGR flow- but he checked the EGR AND the pipe or tube that connects to it when he replaced a fuel injector and both are ok. He mentioned that it could be the oxygen sensor I think. He doesn't have the smog testers and suggested that I take it to a smog mechanic too.
I didn't see him today- so I did not get the exact codes.


If I go in for a smog test- will my car be registered w/ DMV as failing?
Can I ask for a specific test instead of a complete smog inspection?

I looked on the internet for smog stations near me and the reviews inspire hesitancy which is why I'd like to go in for a specific test or question.

Thank you all again! You've been very helpful!