high CO emissions
January 5th, 2009, 10:00 PM
#11
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RE: high CO emissions
price the dealer if it is not much more than aftermaket and if you plan on keeping the truck for another 14 years go with the dealer cat. Walker or eastern make a decent aftermarket. Nothing will last as long as oem
January 22nd, 2009, 8:40 PM
#13
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High CO means you are over-fueling, but burning it (strong ignition system).
Have you checked the $30 O2 for being stuck low?
The thermostat for opening early?
Sounds like you live in a non dyno-run emissions county (no NOx). A decently tuned engine should pass a idle/reved up test w/out even having a cat!
Have you checked the $30 O2 for being stuck low?
The thermostat for opening early?
Sounds like you live in a non dyno-run emissions county (no NOx). A decently tuned engine should pass a idle/reved up test w/out even having a cat!
January 23rd, 2009, 3:44 PM
#14
I'd be checking the O2 as well, Also maybe running a quality injector cleaner through it or getting a shop to clean the injectors.
Before you replace the cat, you can have it tested if a shop has the equipment do so. Like a tech has already told you, the first tell tale sign, is a temp difference. Using a temp gun, after the engine has been fully warmed up read the temp pre and post cat. It should be 100 degrees hotter post cat.
If it is hotter pre cat, then your looking at a plugged converter. If the temp is the same, then there is more than likely a hole melted through the middle of it, or someone has knocked the honeycomb out of it.
You can also drill holes pre and post cat and take readings to see if the cat is performing properly
Before you replace the cat, you can have it tested if a shop has the equipment do so. Like a tech has already told you, the first tell tale sign, is a temp difference. Using a temp gun, after the engine has been fully warmed up read the temp pre and post cat. It should be 100 degrees hotter post cat.
If it is hotter pre cat, then your looking at a plugged converter. If the temp is the same, then there is more than likely a hole melted through the middle of it, or someone has knocked the honeycomb out of it.
You can also drill holes pre and post cat and take readings to see if the cat is performing properly
January 23rd, 2009, 10:19 PM
#15
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If the 02 was stuck lean/low pcm would dump fuel that was truely not needed Which would intern rasie the HC reading. HC is unbured fuel. TRUCK PASSED HC PERFECTLY,not even close to limit. So where did it go?
January 24th, 2009, 10:58 AM
#17
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It can not burn all of it especially at idle and HC is not elevated. Also that would not be very efficent which would make the co2 come way down. This reading is perfect not going to get much better on a vehicle of this age. Have you ever actually seen a vehicle with a bad 02 on a 5 gas analyzer. We have 2 at my shop, I use them daily. The other possiblity is the truck was not conditioned properly for the test (hot enough) which would raise the co reading. I have had many customers drive 5-10 min to the test station and fail only to bring it to me, I drive it put it on our 5 gas analyzer and number are perfect. The customer returns to the test with a fully warm engine and passes with no repairs
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