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high flows cats installed.. car feels sluggish

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high flows cats installed.. car feels sluggish

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Old 02-28-2007, 12:02 AM
  #1  
sipynsyrup
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Default high flows cats installed.. car feels sluggish

well because my car wouldnt pass emissions with no cats and did bad on the tail-pipe test.. I had to RUIN my full mac exhaust(headers-back) with some cats. I went to a local exhaust shop and at first wanted them to connected the 2 cats with flanges so I could just put a testpipe after inspection and put it back whenever needed, BUT they quoted me $600!!!! **** THAT!!!.. It was $336 for the 2 cats and labor.... after picking it up after work.. I drove it home and the car was running horrible... does it just take time for the computer to adjust?? That is what the guy told me...

all I know is that my car doesnt sound NEARLY as good and kinda sputters a little when I punched it.


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Old 02-28-2007, 12:06 AM
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93 LX FiveO
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Default RE: high flows cats installed.. car feels sluggish

do you have 02 sensors? do they work?

what kind of cats did u buy?
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Old 02-28-2007, 12:17 AM
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sipynsyrup
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Default RE: high flows cats installed.. car feels sluggish

ORIGINAL: 93 LX FiveO

do you have 02 sensors? do they work?

what kind of cats did u buy?
Im not sure.. I never checked... the car was running fine beforehand...

not sure on the brand, but they are high-flow cats that they had there in the shop.

I do have the egr deleted, but it was deleted a long time ago and never gave me any problems before..


He told me to make sure I drive a minimum of 50miles before I go get inspected so the computer can readjust to the new cats(??)
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Old 02-28-2007, 01:07 AM
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black89gt
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Default RE: high flows cats installed.. car feels sluggish

do you still have your smog system hooked up? if not, you will clog those cats in no time.
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Old 02-28-2007, 01:58 AM
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Twisted
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Default RE: high flows cats installed.. car feels sluggish

First thing I'd try is resetting the computer. It seems unlikely that the computer would adjust to the cats during the first running.
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Old 02-28-2007, 02:37 AM
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vristang
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Default RE: high flows cats installed.. car feels sluggish

The computer will not make ANY adjustments because of the cats. It can't, as the O2's are before the cats (unless the shop really f'd up your car...)

The 50 miles of driving is to 'break in' the cats. Brand new cats are actually a little less efficient. They need some good heat cycling to get into their prime.
It has nothing to do with the computer.

If the welder is smart, he disconnected your battery before working on the car. This would reset your KAM, so some time may be needed to get things back to normal. The 50 miles for the cats will be plenty for the KAM values to rebuild.

Pull your codes.
It is possible that they busted a sensor or something in the process of installing the cats.


IF the cats were not appropriately sized, then power loss can occur.
Properly sized cats won't cost you any power though.


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Old 02-28-2007, 03:18 AM
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sipynsyrup
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Default RE: high flows cats installed.. car feels sluggish

alright.... earlier I decided on taking the car out for another spin.. this time the car was acting right... it didnt act like it did earlier... I'm going to reset the computer in the morning anyways. I am also going to drive to a friends house to break the 50mile mark before I take it to get inspected, or should I drive farther and get some exhaust flowing ;-)?

My car is lowered so I cant really see much unless I jack it up and look at his work. I saw the cats, but didnt look hard to see if there were o2's connected to the car. My egr is deleted and the header is capped. The CEL does come on, but when I run my obdI it only mentions codes regarging the egr.

The high-flow's dont hinder performance???
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Old 02-28-2007, 03:36 AM
  #8  
aode08
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Default RE: high flows cats installed.. car feels sluggish

check the passenger side 02 sensor, see if they left it loose or used vise grips to tighten it, if so, replace it.

also if a torch was used, check the rear plug wires and associated 02 wiring
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Old 02-28-2007, 03:43 AM
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vristang
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Default RE: high flows cats installed.. car feels sluggish

ORIGINAL: sipynsyrup

The high-flow's dont hinder performance???
Not enough to register on your SOTP meter.
The cats MUST be appropriately sized though.
Are you confident your shop picked the right size? Are you sure you were given a decent brand?

ORIGINAL: sipynsyrup

alright.... earlier I decided on taking the car out for another spin.. this time the car was acting right... it didnt act like it did earlier... I'm going to reset the computer in the morning anyways. I am also going to drive to a friends house to break the 50mile mark before I take it to get inspected, or should I drive farther and get some exhaust flowing ;-)?
If the car is running right, then there is no need to reset the KAM again. This will just cause the car to run like poo while it relearns your motor, again.


ORIGINAL: sipynsyrup
My car is lowered so I cant really see much unless I jack it up and look at his work. I saw the cats, but didnt look hard to see if there were o2's connected to the car. My egr is deleted and the header is capped. The CEL does come on, but when I run my obdI it only mentions codes regarging the egr.
The EGR will trigger the CEL, so that seems normal.

I just realized that you had a 94. Since I am not very familiar with these cars, I will let someone else chime in here...



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Old 02-28-2007, 03:49 AM
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sipynsyrup
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Default RE: high flows cats installed.. car feels sluggish

alright thanks

would my obd1 pick up a bad o2?? What code would it throw, or what would the code say??

I am going to run the test tomorrow and also check to see if everything is connected. I am positive that a torch was used(they always use cutting torches to cut it off and weld it on. I hope he was smart enough to disconnect the battery while welding.
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