Hey there. My 94' 850 is idoling funny and there are horrific gas fumes coming out the exhaust. So bad that I'm afraid to drive my wife and 7 month old! Windows up or down the fumes get me high every drive!

I'm leaning toward a vacuum line but that just kind of explains the idol right? Its not mis-firing, it drives nice and strong when I'm on the gas, but when I left of the throttle it just bogs and sputters, instead of the rpms dropping nicely. And a vacuum leak big enough to cause HORRENDOUS fumes would impact performance more right?

Does anybody know what these codes mean? Could it be an O2 sensor or something? Or do I have an idol circuit module or something that's messing up my computer? because i'm definitely not burning fuel properly...


1-2-1
Manifold Absolute Pressure (MAP) signal absent or faulty

5-1-1
Adaptive oxygen sensor control, provides leaner mixture at idle

5-1-2
Oxygen intergrator at maximum lean running limit

I'd love any help I can get! Thanks everybody!

 

1-2-1
Manifold Absolute Pressure (MAP) signal absent or faulty

5-1-1
Adaptive oxygen sensor control, provides leaner mixture at idle

5-1-2
Oxygen intergrator at maximum lean running limit[/quote]

You should most likely replace the Mass Air Flow sensor. You should check to make sure it's plugged in first. Taking the connector off and pushing it back on and clearing the code would be a good check. It is the sensor that is bolted to the air filter housing. Go to any parts store web page and punch in your car and then the sensor by name and it will show you a picture of what you're looking for. The 1-2-1 code would indicate it's bad. You could remove it and try to clean it. Use only something that says it's made to clean that MAF sensor ( 4-7 bucks) as a carb or brake cleaner can damage it.
You can also go to a parts store and borrow their code scanner to read and reset your check engine light but if it's running that badly is a hard fault.
Once it's replaced you need to reset the light and then see if that's cured the other codes you have. They could be caused by the bad sensor as the computer can not properly control the air fuel mixture without knowing how much air is coming in past that MAF sensor.

 

I did unplug my MAF sensor yesterday and tried to drive it and it wouldn't run. It'd start and then die, even in neutral with my foot on the gas. Just wouldn't stay running at all...

Do you think it could still be the MAF sensor?

P.S. Thanks for the heads up about the cleaner haha! I would have totally used carb cleaner.

Thanks for your help!

 

Likely a vacuum leak somewhere.

 

check for vacuum leaks everywhere even in the evap system. definitely try cleaning the maf only with MAF cleaner. try to pick up a spare maf at a junkyard to see as well.

 

Clear the codes, re read the codes and see if MAF pops up again. YES, check for a vac leak all the up to the throttle body. If you clean the throttle body you also need to use a cleaner for that application. The throttle plate has a coating to keep it from corroding and from getting wedged in the bore. Once again, don't use carb cleaner on this one either. I'm not sure how it would cause a MAF code but you might want to pull the cap, rotor and plugs to see if they look clean and you're hitting on all five if you haven't all ready.

 

Hey guys. Thanks for all your help. Just wanted to update. found the issue. a vacuum leak haha. running great now, hopefully it lasts and that was really it. This is what was lose. I pulled off the idol control unit and found the bolt was loose and the main hose had a gap in it between the manifold and hose

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this is another zoomed out picture of what was loose (ignore the arrows/words)
http://www.google.com/imgres?q=volvo...:429,r:11,s:22