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Exhaust and Carbon Monoxide

Exhaust and Carbon Monoxide

skituc

Jeeper
Posts
32
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Location
Tucson, AZ
Vehicle(s)
1985 CJ7,2.5L 4cyl,4 speed trans
Hey all I have been trying to get my carbon monoxide levels down on my 1985 CJ7 (4cyl, stock height, 31x10.5). I recently put a new fully enclosed complete soft top on my jeep for winter and smelled exhaust. I used a RAE four gas monitor to measure the CO levels and found high Parts Per Million levels. 35 PPM sets the meter off and I was averaging 60 - 80. I know OSHA and NIOSH set a 35 PPM for an 8 hour shift and a ceiling exposure of 200. I had a shop replace my Cat, muffler and piping. Now my CO levels seem higher? the Shop ran the tailpipe straight out the back instead of where the old one exited behind the tire, would that make a huge difference? I'm wondering if the right Cat was used?
 
I have never owned another vehicle that pulls in exhaust like a CJ. Mine was a clean burning Ca. emmissions equiped model :rolleyes: that would pass smog tests no problem yet was really unpleasant to drive and nearly undriveable with rear window rolled up even though the doors would be off. My ultimate fix was fuel injection and now exhaust is completely unnoticed with a side benifit of greatly increasing fuel milage.

You would be better off with the exhaust exiting out the side imo.
 
Hey all I have been trying to get my carbon monoxide levels down on my 1985 CJ7 (4cyl, stock height, 31x10.5). I recently put a new fully enclosed complete soft top on my jeep for winter and smelled exhaust. I used a RAE four gas monitor to measure the CO levels and found high Parts Per Million levels. 35 PPM sets the meter off and I was averaging 60 - 80. I know OSHA and NIOSH set a 35 PPM for an 8 hour shift and a ceiling exposure of 200. I had a shop replace my Cat, muffler and piping. Now my CO levels seem higher? the Shop ran the tailpipe straight out the back instead of where the old one exited behind the tire, would that make a huge difference? I'm wondering if the right Cat was used?

Hi CO's are caused by not having enough air for the combustion process. Some causes are dirty air filter, carb float, dirty oil, saturated charcoal canister or the PCV system. Start with the easy stuff ,good luck.
 
Every CJ that I have been in that exhaust out the back sucked it right into the cab. On mine I used an exit behind the wheel and did not have a problem.
 
Every CJ that I have been in that exhaust out the back sucked it right into the cab. On mine I used an exit behind the wheel and did not have a problem.

Exactly right. The air flow at the immediate back of a Jeep is a swirl effect that brings the air up and back in. Exiting the exhaust right at the corners of the Jeep resolves the problem.
I have dual exhaust strung out to both corners and have no issues with exhaust fumes in the cab.
 
Thanks guys for your input, I did notice the shop put some generic Cat without the Pulse Air hook up, don't know if I can tap into the side of it or just get the right one with the "Air Tube Kit" included. Then bend tailpipe to exit behind the wheel.
 

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