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removing rear o2's

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Old 01-04-2010, 06:41 PM
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Default removing rear o2's

Had my truck tuned today at a local shop. the tuner told me that if i remove my rear o2 sensors and have him get rid of the check engine light that when i get emissions tested i will fail because it will tell there computer that my rear o2 system is undetected. is this true? is there away around this I would like to ditch the cats and rear o2s and not have to worry in a few years about having the cats all put back on and a retune. I like in AZ and they dont look under your vehicle inless they have a reason or its obd1.
Old 01-04-2010, 06:45 PM
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Don't know if their system will read them as off or as no errors. There are some devices you can put on them where they stay on but read good all the time.

Don't remember what it's called.
Old 01-04-2010, 06:45 PM
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The guy that tuned it doesn't know what he is talking about....

You could fail inspection because of visual inspection with no cats, but they cannot tell that the rear O2s are gone if it is tuned properly


That is assuming that AZ OBDII emission testing is the same as most TX counties.
Old 01-04-2010, 06:50 PM
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Originally Posted by 00ChevyScott
The guy that tuned it doesn't know what he is talking about....

You could fail inspection because of visual inspection with no cats, but they cannot tell that the rear O2s are gone if it is tuned properly


That is assuming that AZ OBDII emission testing is the same as most TX counties.
I was kinda thinking the same thing haha o well he should take the rear o2's out for free for me when i get a chance. any one else heard of this ?
Old 01-04-2010, 07:21 PM
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Originally Posted by 00ChevyScott
The guy that tuned it doesn't know what he is talking about....

You could fail inspection because of visual inspection with no cats, but they cannot tell that the rear O2s are gone if it is tuned properly


That is assuming that AZ OBDII emission testing is the same as most TX counties.
x2

all he needs to do is disable them...
Old 01-04-2010, 09:25 PM
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Originally Posted by viciousknid
Don't know if their system will read them as off or as no errors. There are some devices you can put on them where they stay on but read good all the time.

Don't remember what it's called.
Are you referring to the spark plug defoulers that some guys have used? (I believe that Joe<hirdlej> used them on one of his work trucks with good results)
Old 01-04-2010, 09:47 PM
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Originally Posted by SILVERADO11
I was kinda thinking the same thing haha o well he should take the rear o2's out for free for me when i get a chance. any one else heard of this ?
no o2's for over 2yr and they havn't fail it. Thunder550, Dustin, deven, jeff, Aj will tell you the same thing
sorry I would give you there names here on the board but i'm using the phone right now while waiting for kid to go to sleep.
Old 01-04-2010, 10:16 PM
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Originally Posted by 53RUSSELL
no o2's for over 2yr and they havn't fail it. Thunder550, Dustin, deven, jeff, Aj will tell you the same thing
sorry I would give you there names here on the board but i'm using the phone right now while waiting for kid to go to sleep.
hey thanks for the info, looking forward to geting rid of the cats.
Old 01-04-2010, 10:51 PM
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Here's the deal in AZ:

Remove the cats and rear O2's. Have your tuner disable the rear O2 emissions codes and monitoring.

In AZ, OBDII vehicles are tested by checking the gas cap, sometimes a visual inspection, and scanning the PCM for emissions codes and readiness tests. As long as you have no codes and no more than one readiness test that has not completed you will be fine.

That being said, don't reflash your computer and head straight to the emissions test...you need to drive the thing for at least a little bit to let all of the readiness tests finish (except the O2 readiness test - it will not finish because the rears are gone).

First time I passed emissions was one day after finishing my 6.0L swap. Tune was garbage since I hadn't had time to tweak it, had blower, long tubes, big cam, no cats, engine was loping like crazy and trying to die every time I let off the gas. The guy popped the hood and didn't even blink at the blower or longtubes. Hooked up the scanner, no codes, all readiness tests except O2 had completed, checked the gas cap, and sent me on my way. Second time I had a bad turbo and was burning a little bit of oil, they never even popped the hood that time.
Old 01-04-2010, 10:58 PM
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Originally Posted by thunder550
Here's the deal in AZ:

Remove the cats and rear O2's. Have your tuner disable the rear O2 emissions codes and monitoring.

In AZ, OBDII vehicles are tested by checking the gas cap, sometimes a visual inspection, and scanning the PCM for emissions codes and readiness tests. As long as you have no codes and no more than one readiness test that has not completed you will be fine.

That being said, don't reflash your computer and head straight to the emissions test...you need to drive the thing for at least a little bit to let all of the readiness tests finish (except the O2 readiness test - it will not finish because the rears are gone).

First time I passed emissions was one day after finishing my 6.0L swap. Tune was garbage since I hadn't had time to tweak it, had blower, long tubes, big cam, no cats, engine was loping like crazy and trying to die every time I let off the gas. The guy popped the hood and didn't even blink at the blower or longtubes. Hooked up the scanner, no codes, all readiness tests except O2 had completed, checked the gas cap, and sent me on my way. Second time I had a bad turbo and was burning a little bit of oil, they never even popped the hood that time.
Great info thanks alot!
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