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Discussion Starter · #1 ·
The burb failed its smog test yesterday. CO levels were a tad high. Took it to a test only station and besides the CO, the gas cap did not pass either. I thought I'd start with cleaning the K&N and a fresh set of plugs. Any suggestions?
 

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Did you drive it at least a half hour before the smog test was done?

If you did not it may have still been in the start up mode. High fuel or whatever it’s called. I know when we lived in Taxachusetts if the vehicle wasn’t warmed up it would never pass.
 

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Try running some fuel injector cleaner/engine treatment through it. If you had failed on NOx then I would have suggested EGR or Cat, but CO just sounds like it is dirty somewhere. And as Fiero said, warm it up real nice. Good luck.
 

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Discussion Starter · #4 ·
Cool, I'll give it a try. Stay tuned for test#2 results.
 

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Discussion Starter · #5 ·
New plugs and air filter. Dumped a can of seafoam in the tank and going for a retest today. Plugs 1 & 3 showed signs of wear. Hope for the best.
 

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Good luck! Don't forget about 10 mile tour at freeway speeds then go right in to be tested. Don't shut it off when you get there.
 

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Discussion Starter · #7 ·
Failed test #2. The 1st tech was a tard! The second tech spotted it right away. Bad cat! Quoted $140 for a cat or $340 for cat and a cat back system with a Magnaflow and 3" pipe with the mandatory chrome tip. Went for the whole package and the 3rd test passed! Whoopee:party:
Sounds mellow enough too. Can't wait for the Cajon Pass climbing test to see if there are any extra benefits in the HP department.
 

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Plugged cat? Well I'll be damned. I'm surprised you didn't feel that earlier...? Anyway good for you, an unexpected upgrade. :great:
 

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Discussion Starter · #9 ·
Plugged cat? Well I'll be damned. I'm surprised you didn't feel that earlier...? Anyway good for you, an unexpected upgrade. :great:
Cat wasn't plugged, just worn out. 240k and it was done. btw went to a test only station, so they weren't trying to sell me anything. Howard's Muffler quoted me a fair price and got the job done the same day!:great:
 

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See, I told you so!! :lol: I have the Magnaflow catback on my 99 and love it. Nice mellow tone and a few more ponies pushing it.
 

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mmine passed with 310,000+ miles and the tech said it was going to fail right off the bat so he cut the final somg check price for being way wrong.....not bad for a 93 vehicle....mike
 

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When I took our 1990 GMC Suburban(329,000 miles) in last time, the tech said that it looked as though it was going to fail, but when he revved it up a bit, it passed. He told me that the blended gasoline with ethanol made a big difference with these engines, (5.7L) and suggested that before I bring it in to get inspected the next time, that I run at least one tank full of pure gasoline, not that blended ethanol stuff.
 

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Discussion Starter · #13 ·
Whooee! Ran it through the Cajon Pass HP test and it ran great. Before the cat back / magnaflow I could not use the cruise control to climb the 4% grade. It would start to slow, then the cruise would drop out. This time I set the cruise for 70mph and rode it all the way to the top without missing a beat.:biggrin:
 
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