Aftermarket Exhaust Setup CATs/O2/spacers/Alignment/XForce

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Aftermarket Exhaust Setup CATs/O2/spacers/Alignment/XForce

Postby Shaheenis » Sat Nov 23, 2013 1:32 pm

Guys,

Thought I would start a new thread as I have already searched and read heaps of threads on here where some of my questions have been answered but not all. I have also posted some questions in other threads with no response :(.

My questions relate mostly to the location of O2 sensors and mating an aftermarket exhaust to stock mufflers.

O2 Sensor & CAT
My understanding is that there is an O2 sensor pre-turbo and post cat. The ECU measures the effeciency pre and post and throws an error if not enough carbon emissions has been removed.

:?: Q1. Do most aftermarket exhausts have a O2 bung in the mid-pipe post cat? I am specifically interested in XForce. I am just wondering if I bought a XForce TBE delete muffs, where would the O2 bung be?

Apparently the CAT in dump is the best location. Either way I have noted that some good brands have this as either standard or option. XForce do a dump with what they call a pre-cat. Link to Xforce Dump with Pre-cat

:?: Q2. Do you think this would be enough (without any other CAT) to stop the CEL from being thrown? as it only costs $24 more I can't imagine it does much to reduce emissions which makes you wonder why it is even an option. Or alternatively, this in combination with a 100 CAT should stop CEL?

:?: Q3. If I deleted the CAT post downpipe with an Xforce TBE, would I need a custom pipe (length of CAT) to fill the void?

Fitment, Alignment and Stepping
I have heard that people fitting aftermarket TBE with stock mufflers can have alignment issues and require bending of mounts or heating with pole in muffler etc to fix.

:?: Q4. Has anyone done/considered elongating the flange holes to allow for minor re-alignment/rotation prior to tightening?

I understand that the factory muff inlet pipes are 1.8" and the XForce are 2.5". Although the pressure is lower at the rear of the car I still do not like the down size step as I believe it will cause turbulance and may impede optimal air flow.

:?: Q5. Has anyone created a tapered spacer to smooth airflow or port matched the mufflers with a die grinder (assuming there is enough meat on the flanges without destroying the welds?

Cheers in advance. Hoping keeping all this information together will benefit others also.

Cheers,
Shaheenis
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Re: Aftermarket Exhaust Setup CATs/O2/spacers/Alignment/XFor

Postby blacktop™ » Sat Nov 23, 2013 2:41 pm

I've only got answers for q2 &q3.

If they call it a pre-cat and only costs $24 more, I can only assume it's to be used in conjunction with another cat...prob a 100 cell cat.

With that being said, the non-cat version will need a cat (or a replacement pipe if that's the risk you want to run) and it's fairly safe to assume that the 'pre-cat' dump will need a cat too. A quick email to force can confirm this.

Personally I'd go for the version without a cat if you're gonna need put a cat in anyway as it's cheaper and will provide less restriction.
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Re: Aftermarket Exhaust Setup CATs/O2/spacers/Alignment/XFor

Postby Shaheenis » Sat Nov 23, 2013 3:16 pm

Thanks Blacktop but haven't people had issues running a 100CEL CAT only too? or only with no CAT?
Shaheenis
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Re: Aftermarket Exhaust Setup CATs/O2/spacers/Alignment/XFor

Postby blacktop™ » Sat Nov 23, 2013 3:22 pm

I'm not really sure what cat most guys use on here...but I do know that most get that emissions cat CEL thingo disabled when they get their cars tuned.
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