CK5
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Soup: Emissions - what can i remove
- Thread starter soupman
- Start date
does your truck have to get a sniff test or just visual inspection of emmisions? Does it even require anything beyond a safety inspection being over 25 years old?
Properly running most vehicles can pass with a converter and none of the other junk. Thats a sniff test. Visual inspection, there prety much isn't anything on that motor that isn't part of the emissions system.
A newer converter is more likely to work better, plus free up some power. The old flat pellet-type converters sucked.
Removing things like EGR will lead to a part throttle lean condition, whether or not you notice it is probably dependent on your truck, driving style, etc.
A newer converter is more likely to work better, plus free up some power. The old flat pellet-type converters sucked.
Removing things like EGR will lead to a part throttle lean condition, whether or not you notice it is probably dependent on your truck, driving style, etc.
It depends on the year, most 49 state trucks only had pcv, egr, exhaust flapper on one manifold and stock air cleaner. Also make sure your timing is set right..
If you search google there is a list of the trucks and years they got certain things..
My 79 ca k5 has Thorley headers smog legal with the cat and flapper, timed vaccum for dist, pcv,egr, heat pipe to front of air cleaner and that's it..
I had a 78 k20 that had tru dual no cats and only pcv egr and heat pipe that's it.. and some of this stuff doest hurt power at all.. smog pumps and air. does..
If you search google there is a list of the trucks and years they got certain things..
My 79 ca k5 has Thorley headers smog legal with the cat and flapper, timed vaccum for dist, pcv,egr, heat pipe to front of air cleaner and that's it..
I had a 78 k20 that had tru dual no cats and only pcv egr and heat pipe that's it.. and some of this stuff doest hurt power at all.. smog pumps and air. does..
I'd be real careful about pulling junk off it then.
Had a 305 in my '83, extremely noticeable lean surge at cruise when I pulled EGR, that would have definitely failed sniff test. Nothing on there is "just because". If GM could have removed it, or didn't need it, it wouldn't be there. All of it's tied together, and all of it is stuff that will affect emissions in one form or the other unfortunately. Still able to pass plugging a port on a thermal vacuum switch? I wouldn't make that bet.
If you don't like the emissions on there, seriously consider swapping to TBI. Lot less junk underhood in terms of hoses, better performance, and will test cleaner if it's not monkeyed with.
Had a 305 in my '83, extremely noticeable lean surge at cruise when I pulled EGR, that would have definitely failed sniff test. Nothing on there is "just because". If GM could have removed it, or didn't need it, it wouldn't be there. All of it's tied together, and all of it is stuff that will affect emissions in one form or the other unfortunately. Still able to pass plugging a port on a thermal vacuum switch? I wouldn't make that bet.
If you don't like the emissions on there, seriously consider swapping to TBI. Lot less junk underhood in terms of hoses, better performance, and will test cleaner if it's not monkeyed with.
