smog question
10-12-2012, 02:49 PM
#13
Senior Member
Let me see if I can make a comprehensive, easy-to-read post.
There are 4 possible criterion for each of us to be in.
1. Have a catalytic converter and a oxygen sensor downstream of the cat.
2. Have a catalytic converter, but the oxygen sensor is upstream (closer to the engine) from the cat.
3. Have no catalytic converter, but the oxygen sensor used to be downstream of the catalytic converter.
4. Don't have either a catalytic converter or a oxygen sensor that was downstream of the catalytic converter that used to be on it.
For each of those scenarios, there are potential consequences.
For #1: If you delete your air pump, your oxygen sensor will be reading that your cat is bad, and will tell the computer to compensate, leading to codes/running problems/etc. Also, your cat will become clogged leading to the aforementioned running problems/engine damage/etc.
For #2: If you delete your air pump, your truck will run fine until your cat becomes clogged, then you will have the latter of the problems mentioned in #1.
For #3: By not having a cat, you have already created a potential future problem, because the oxygen sensor will be reading that your cat is bad, and tell the computer to compensate, leading to more aforementioned problems. Also, you should have already figured out what you are doing with your own air pump when you deleted the cat, because you had to unhook the line then.
(unless a previous owner did it)
For #4: You should have also already figured out what you were doing with your air pump. If you haven't, just do with it what you wish, because having it or not makes no difference to you or your truck's computer.
Now that that's over with, I feel like I wasted my time, but I know I didn't because without this post there would be someone later that didn't understand what Warlokk was saying (or didn't want to understand) asking about their specific situation. (there probably still will be someone) cough
There are 4 possible criterion for each of us to be in.
1. Have a catalytic converter and a oxygen sensor downstream of the cat.
2. Have a catalytic converter, but the oxygen sensor is upstream (closer to the engine) from the cat.
3. Have no catalytic converter, but the oxygen sensor used to be downstream of the catalytic converter.
4. Don't have either a catalytic converter or a oxygen sensor that was downstream of the catalytic converter that used to be on it.
For each of those scenarios, there are potential consequences.
For #1: If you delete your air pump, your oxygen sensor will be reading that your cat is bad, and will tell the computer to compensate, leading to codes/running problems/etc. Also, your cat will become clogged leading to the aforementioned running problems/engine damage/etc.
For #2: If you delete your air pump, your truck will run fine until your cat becomes clogged, then you will have the latter of the problems mentioned in #1.
For #3: By not having a cat, you have already created a potential future problem, because the oxygen sensor will be reading that your cat is bad, and tell the computer to compensate, leading to more aforementioned problems. Also, you should have already figured out what you are doing with your own air pump when you deleted the cat, because you had to unhook the line then.
(unless a previous owner did it)For #4: You should have also already figured out what you were doing with your air pump. If you haven't, just do with it what you wish, because having it or not makes no difference to you or your truck's computer.
Now that that's over with, I feel like I wasted my time, but I know I didn't because without this post there would be someone later that didn't understand what Warlokk was saying (or didn't want to understand) asking about their specific situation. (there probably still will be someone) cough
Last edited by James 302; 10-12-2012 at 05:28 PM.
10-12-2012, 05:27 PM
#16
Senior Member
10-12-2012, 05:57 PM
#17
Senior Member
Nice summary James. One last thing I want to add is there at plenty of junk yard pumps around for cheap. So as there is no advantage to deleting the system other than looking a few pounds it seems silly to do the work simply to create more smog. The parasitic drag is less than the alternator and uses less power than carrying a full size spare tire. I'm no tree hugging hippy ( I'm not driving a Prius) but I don't see the sense in going out of my way to create pollution. That is the kind of thing that causes environmental activists to pass more junker laws and inspection laws. Diesel vehicles are now being regulated and motorcycles are comming up soon.
10-12-2012, 06:20 PM
#18
Originally Posted by f150cam
the 02 after the cat has nothing to do with air/fuel, its just there to tell you that your cat is bad.
Originally Posted by James 302
Yeah you're exactly right. That's what I meant to say. Fixed :p
10-12-2012, 06:25 PM
#20
Okie.
Originally Posted by LobstahClaw
This is just speculation on my part:
I think we're generally in agreement that it's a good idea to keep the EGR in place and working well. It makes a positive contribution to improved fuel milage.
The smog pump dumps air into one of three places.
1: Upstream of the 02 sensor into the exhaust manifold.
2: Downstream of the 02 sensor into the cat
3: Directly into the atmosphere.
I've got to wonder if dumping fresh air into the exhaust manifold preps the exhaust for reintroduction via the EGR valve.
If you're sucking "dirty" exhaust into your intake manifold it will cause a buildup of carbon in the intake manifold.
That will create drag and alter the air flow charecteristics of the intake so that you're not getting a good fuel/air mix.
The result has got to be a less than complete burn in the cylinder. That would mean less power,lower fuel milage, and even dirtier emissions.
If it is like this, then it's not like you take your air pump off and a week later everything goes to the dogs.
It's more like a long slow decline of performance till a few years later the overall condition of things has become so degraded that the truck really doesn't run very well anymore.
It's like the domino effect.
Of course ... in the mean time you're apt to get all kinds of engine codes as individual parts of the motor begin to fail.
I think we're generally in agreement that it's a good idea to keep the EGR in place and working well. It makes a positive contribution to improved fuel milage.
The smog pump dumps air into one of three places.
1: Upstream of the 02 sensor into the exhaust manifold.
2: Downstream of the 02 sensor into the cat
3: Directly into the atmosphere.
I've got to wonder if dumping fresh air into the exhaust manifold preps the exhaust for reintroduction via the EGR valve.
If you're sucking "dirty" exhaust into your intake manifold it will cause a buildup of carbon in the intake manifold.
That will create drag and alter the air flow charecteristics of the intake so that you're not getting a good fuel/air mix.
The result has got to be a less than complete burn in the cylinder. That would mean less power,lower fuel milage, and even dirtier emissions.
If it is like this, then it's not like you take your air pump off and a week later everything goes to the dogs.
It's more like a long slow decline of performance till a few years later the overall condition of things has become so degraded that the truck really doesn't run very well anymore.
It's like the domino effect.
Of course ... in the mean time you're apt to get all kinds of engine codes as individual parts of the motor begin to fail.
Originally Posted by Just call me Sean
Smog pump has no effect on that.