1994 Chevrolet Truck wont pass smog

1994 CHEVROLET TRUCK
350,000 MILES • 4.3L • 6 CYL • 2WD • MANUAL
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MAQSR1122
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  • 1 POST
I have been trying to get my truck to pass smog. It wont. The guy at the station says its running to rich. another guy said, it was a vacuum leak, another guy said, I might have a cracked exhaust manifold.
A few years ago while I was having a cat installed I recall the muffler shop guy saying that the exhaust manifold might be cracked. I do get a check engine light, often. It seems like it happens more when I down shift to slow down. I purchased my truck new, it has well over 350,000 miles. Odometer stopped at 280,000. that happened like 10 years ago.
Mar 25, 2015 at 8:54 PM
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HMAC300
  • ✓ASE Certified Mechanic
  • 48,601 POSTS
  • ASE Certified Mechanic
find out exactly what it is doing running rich or lean and wheteher the manifold is cracked or not. if it is fix it it shold be making noise if it is. exhaust leaks cause air leaks so it thinks it's lean and will richen the fuel mix.
Mar 26, 2015 at 6:10 AM
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