Adding Flex Tube to Down Pipe

So, I am wanting to add a flex pipe to my down pipe. I would like to install it to the section of pipe just before my cat. The reason I thought this would be a good idea is the cross member that keeps the transmission up has a hanger on it. I am just installed a new APN header and want to keep from stressing it. Has any one done this and if so, how is this holding up?

The one i'm looking at is http://www.summitracing.com/parts/PSM-82-4216/

ive seen more flex pipes leak in a short period of time than last a decent amount of time. id install new motor mounts an trans mount in an effort to reduce engine movement before i did a flex pipe. they just dont last IMO. i understand wanting to make your APN last. but my stock manifold lasted 160k miles and almost 15 years before it went. most people dont own a car that long... my parents drove my XJ off the lot new. id imagine your experience was more or less similar.

i had a stocker laying around, threw it on, replaced the cat and muffler with cheapies, removed the crushed section of the downpipe.... and then saved myself a lot of money.

I put one on in the position your are talking about. Not sure how much it really helps but I was redoing the whole system at the time anyway. It's been on for about 4 years now and will probably go back on the when I go to rebuild the rest of the exhaust again sometime soon.

Destroyer said:

I put one on in the position your are talking about. Not sure how much it really helps but I was redoing the whole system at the time anyway. It's been on for about 4 years now and will probably go back on the when I go to rebuild the rest of the exhaust again sometime soon.

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This is exactly what I wanted to do, how is your header holding up? By the way nice job looks great.:guitar:

That is a very good idea.

The one you linked to is too big. You need one that is 2.5" OD instead of 3" OD. The early XJ exhaust is only 2.25" while the later ones start at 2.5" and reduced to 2.25" at the silencer. You need to check that before you order. I think 4" in length should be good.

rockchucker said:

This is exactly what I wanted to do, how is your header holding up? By the way nice job looks great.:guitar:

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Thanks, the header is holding up good. It is factory with only 100k on it though. The flex pipe I used was 2.5" in/out and I think 8" long. On a side note, the POR-15 exhaust coating was a complete waste; it was gone within a year.

techno1154 said:

That is a very good idea.

The one you linked to is too big. You need one that is 2.5" OD instead of 3" OD. The early XJ exhaust is only 2.25" while the later ones start at 2.5" and reduced to 2.25" at the silencer. You need to check that before you order. I think 4" in length should be good.

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The Flex part is 3 and the in/out is 2.5. My down pipe goes from 2.25 to 2.5 right under the transmission.