Why aren't Piggies plug and play? Relocate rear O2 sensor?
03-10-2009, 04:11 AM
#1
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Why aren't Piggies plug and play? Relocate rear O2 sensor?
I am at Stage2- (?) [AWE Twin2 and GIAC 93 Program] and thinking about going the next step and opening up the downpipes a bit to extract more power.
If I go with Piggies, what is the deal with the 02 sensors and check engine lights, emissions, etc?
I keep reading how people have to get defoulers, relocate the [rear??] O2 sensor, otherwise they get a light and won't pass emissions.
Was hoping they would be a simple solution but it sounds like there is more involved than just swapping out the DP sections.
(Any input from those that hav them? I am in PA so not sure how "strict" my emissions are relative to other states.)
Lastly - I STFA and believe I read that GIAC program skips the rear 02 sensors? So do I have to worry about this at all??
If I go with Piggies, what is the deal with the 02 sensors and check engine lights, emissions, etc?
I keep reading how people have to get defoulers, relocate the [rear??] O2 sensor, otherwise they get a light and won't pass emissions.
Was hoping they would be a simple solution but it sounds like there is more involved than just swapping out the DP sections.
(Any input from those that hav them? I am in PA so not sure how "strict" my emissions are relative to other states.)
Lastly - I STFA and believe I read that GIAC program skips the rear 02 sensors? So do I have to worry about this at all??
03-10-2009, 04:48 AM
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Ok I'll rephrase. If I get genuine Piggy pipes from VAST will I have problems?
The reason I ask is their web site seems to mention everything is already taken of for the customer:
"Fitment is perfect with the use of OEM parts and stainless steel welds, stainless steel O2 sensor bungs as well as bulletproof OEM Leistritz Catalytic converters which are 400cell per inch, just like any aftermarket catalytic converter. Aftermarket cats in other downpipes on the market have been known to either break or set cat efficiency codes. When your 2.7t engine computer is chipped, expect 20-30hp at the crank and 2-3 tenths and 2-3mph faster in the 1/4 mile."
If these aren't plug and play - why metion the stainless O2 sensor bungs at all? See why I'm confused?
I live in an apartment and can't do this type of install on my car - just making sure my local indy can handle the Piggy install without too much hassle.
Any reports on how emissions are effected?
"Fitment is perfect with the use of OEM parts and stainless steel welds, stainless steel O2 sensor bungs as well as bulletproof OEM Leistritz Catalytic converters which are 400cell per inch, just like any aftermarket catalytic converter. Aftermarket cats in other downpipes on the market have been known to either break or set cat efficiency codes. When your 2.7t engine computer is chipped, expect 20-30hp at the crank and 2-3 tenths and 2-3mph faster in the 1/4 mile."
If these aren't plug and play - why metion the stainless O2 sensor bungs at all? See why I'm confused?
I live in an apartment and can't do this type of install on my car - just making sure my local indy can handle the Piggy install without too much hassle.
Any reports on how emissions are effected?
03-10-2009, 06:20 AM
#5
You're stage 2, not 2-, with chip and catback, and real VAST Piggies have the rear O2 bungs
relocated so you pull the rear O2s longer or get ones with longer wires or splice in longer wires. With the sensors behind the main cat, they should work fine and not throw codes.
Some homemade "Piggies" just have the first cat gutted but don't have the bungs relocated.
Some homemade "Piggies" just have the first cat gutted but don't have the bungs relocated.
03-10-2009, 06:50 AM
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You just have to have the 02s relocated farther back. If "genuine" (LOL) they will be. You'll pass
emmisions and have power as well. If you have "2+" software from say, APR, it eliminates the CEL for the 2ndary O2s completely so even if the O2s aren't relocated, there still is no CEL.
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03-10-2009, 07:16 AM
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Rear O2 is measuring to see if there is a difference from the Front O2 reading
No difference = cats not working => CEL
Difference = cats working => you passed emissions and can go get ice cream
VAST relocates the bung to after the second cat so your rear O2 will still read a difference and you pass.
Stacked defoulers on the original bung moves the O2 sensor out of the exhaust stream to create an artifical difference and you pass.
Make sense?
Difference = cats working => you passed emissions and can go get ice cream
VAST relocates the bung to after the second cat so your rear O2 will still read a difference and you pass.
Stacked defoulers on the original bung moves the O2 sensor out of the exhaust stream to create an artifical difference and you pass.
Make sense?
03-10-2009, 07:42 AM
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Simple steps to understanding VAST piggie pipes.
1) Buy VAST piggies which have new bungs welded in after the secondary, larger cats. The bungs just in front of the secondary cats will be plugged.
2) Install piggies.
3) Your primary O2 sensors that are just ahead of the primary cats (the ones that are now gutted) still go in this spot.
4) Your secondary O2 sensors used to measure post primary cat gases, but since there isn't a primary cat anymore, you need to move these sensors to the rear of the secondary cats so that they can measure the post secondary cat gases instead. Some people use the stock secondary O2 sensors and they just barely make it the extra ~18 inches to the new bungs. I bought new lengthed O2 sensors from VAST.
4 optional) Leave the secondary O2s where they are and have special ECU software eliminate the CEL.
2) Install piggies.
3) Your primary O2 sensors that are just ahead of the primary cats (the ones that are now gutted) still go in this spot.
4) Your secondary O2 sensors used to measure post primary cat gases, but since there isn't a primary cat anymore, you need to move these sensors to the rear of the secondary cats so that they can measure the post secondary cat gases instead. Some people use the stock secondary O2 sensors and they just barely make it the extra ~18 inches to the new bungs. I bought new lengthed O2 sensors from VAST.
4 optional) Leave the secondary O2s where they are and have special ECU software eliminate the CEL.
