when i take it off and plug the head and tube that runs down to exhauste will my check engine light come on ???how much power will i get from removing it 3to6hp
smog pump removel
- Thread starter howiefisher
- Start date
earleys94gt
Active Member
The smog pump is there to pump fresh air to the cats. Without it, the cats could prematurly wear out; but if you have a o/r pipe no worries. A delete pulley will save you from buying a new belt.
I don't see it causing a CEL, but that issue might occur.
I also don't see any major power gains. It might actually be similar to installing underdrive pullies, less parasitic "drag".
Here is a good article to help you out...
http://www.allfordmustangs.com/techarticles/Smog2.pdf
I don't see it causing a CEL, but that issue might occur.
I also don't see any major power gains. It might actually be similar to installing underdrive pullies, less parasitic "drag".
Here is a good article to help you out...
http://www.allfordmustangs.com/techarticles/Smog2.pdf
blksn955.o
Founding Member
very little if any gains and really if your running a cat'd mid pipe it kills smog numbers. I have heard of people failing by a large margin putting the smog pump back in with no other changes and passing with number far lower than required.
The only reall thing to bypass is the power steering pump to gain power.
The only reall thing to bypass is the power steering pump to gain power.
i have an off road x pipe .no power gains i thought it would .do you still have yours ?i am also putting headers on i heard 10 to 15 hp what do you think ?i am thinking of taking off the smog pump and ac ?
blksn955.o
Founding Member
Yes, the air from the pump basicly works like a blast furnace. It pumps air into the cats to cause the fuel in the cats to burn hotter and "burn off". You remove the air from the pump to the cats and that fuel does not burn off (higher smog numbers) and run a MUCH greater risk of having that unburned fuel stay in the cat. That un-burned fuel can build up and greatly reduce the life of the cat.
A couple months after removing mine, my CEL came on. When I checked the codes, it was because of low voltage in the smog pump circuitry... So yeah, it can cause a check engine light. I dont know why it took so long for my CEL to come on though. I had a chip burnt to shut of my smog pump crap, and my egr and Ive had no CEL since.
Edit: I would buy a short belt before I forked out cash for a delete pulley...
Edit: I would buy a short belt before I forked out cash for a delete pulley...
WhiteCobra95
10 Year Member
- May 2, 2006
- 632
- 176
- 74
Ok, there are a lot of points here to tackle:
+ The function of the smog pump is simple; it pumps air into the exhaust system ONLY after a cold start to help light off the cats. (Catalysts need to heat up to 300 to 400 deg C before they can react.) The first stage pushes air through the heads into the exhaust ports to light the pup cats (coupled close to the header), then it switches to the main cats (under-floor). The engine typically runs rich during this period to give the exhaust unburned HC to mix and burn with the oxygen from the smog pump in the catalyst brick. The smog pump does NOT continuously pump air into the exhaust system. If it did, your cat would melt down half way through the first WOT.
+ Removing the smog pump will not cause any problems other than hurt your cold start emissions. It won't wear out your catalysts early or anything of the sort.
+ There is definitely some torque to be had by removing it, but the actual amount is debatable. The pump is just dumping the air after the cold start procedure has completed. This load is minimal compared to pumping it into the exhaust.
The final decision is kind of a judgment call. If you have to pass emissions tests, removing it will probably hurt your chances if their test is half-ways decent and involves a cold start. If you are running an off-road H/X pipe then you might as well pull it because it isn’t doing anything.
If you do pull it off make sure to cap all of the lines/ports securely. Fresh air making it into the exhaust system will throw off your O2 sensor signal and bias your combustion air/fuel to the rich side. Also, a continuous fresh air leak into or upstream of the cats will ultimately hurt the cats because they will run much hotter than normal.
I hope this helps!
+ The function of the smog pump is simple; it pumps air into the exhaust system ONLY after a cold start to help light off the cats. (Catalysts need to heat up to 300 to 400 deg C before they can react.) The first stage pushes air through the heads into the exhaust ports to light the pup cats (coupled close to the header), then it switches to the main cats (under-floor). The engine typically runs rich during this period to give the exhaust unburned HC to mix and burn with the oxygen from the smog pump in the catalyst brick. The smog pump does NOT continuously pump air into the exhaust system. If it did, your cat would melt down half way through the first WOT.
+ Removing the smog pump will not cause any problems other than hurt your cold start emissions. It won't wear out your catalysts early or anything of the sort.
+ There is definitely some torque to be had by removing it, but the actual amount is debatable. The pump is just dumping the air after the cold start procedure has completed. This load is minimal compared to pumping it into the exhaust.
The final decision is kind of a judgment call. If you have to pass emissions tests, removing it will probably hurt your chances if their test is half-ways decent and involves a cold start. If you are running an off-road H/X pipe then you might as well pull it because it isn’t doing anything.
If you do pull it off make sure to cap all of the lines/ports securely. Fresh air making it into the exhaust system will throw off your O2 sensor signal and bias your combustion air/fuel to the rich side. Also, a continuous fresh air leak into or upstream of the cats will ultimately hurt the cats because they will run much hotter than normal.
I hope this helps!
yeah i have an off road x pipe so i am going to take it off for sure ,but will my check engine light stay on ????
WhiteCobra95
10 Year Member
- May 2, 2006
- 632
- 176
- 74
It depends on what you do with the vacuum lines and the control solenoids (in the fender well).
I'm running bbk unequal shorties and an o/r H-pipe. All I did was plug the two (or three?) vacuum lines and zip tied up with the vacuum line bundle (If I remember correctly, there are four 1/4" lines all loomed together.) I've had it this way for two or three years and no check engine light.
I think the check engine light comes from the driver stage diagnostic when people remove the solenoids, or block off the vacuum line going to the EGR valve. The ECU has to see the feedback sensor for the EGR valve move when it applies vacuum. I left off the EGR tube, but kept the valve in place with a solid home-made gasket and big vacuum cap over the exhaust feed port.
Let me know if need more info or pictures and I can pull the cover off and look at how I did it. It's been a wile and the details are a little fuzzy.
I'm running bbk unequal shorties and an o/r H-pipe. All I did was plug the two (or three?) vacuum lines and zip tied up with the vacuum line bundle (If I remember correctly, there are four 1/4" lines all loomed together.) I've had it this way for two or three years and no check engine light.
I think the check engine light comes from the driver stage diagnostic when people remove the solenoids, or block off the vacuum line going to the EGR valve. The ECU has to see the feedback sensor for the EGR valve move when it applies vacuum. I left off the EGR tube, but kept the valve in place with a solid home-made gasket and big vacuum cap over the exhaust feed port.
Let me know if need more info or pictures and I can pull the cover off and look at how I did it. It's been a wile and the details are a little fuzzy.
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