i got a M2 DP, there was NO fitment problems.
i didnt even have to take the studs out.

when i put on my Ebay set, the hardest part was getting to the bolts. I used the mid pipe it came with and saved the stock for emmissions.

i was thinking about doing that, but you have to have a tuneable ecu for a mid pipe. i dont have one, and having to retune the car and put the cat back on the car is just too much work.

So uhh, after reading this thread anyone in the Bay Area want to help with a downpipe install? :D I'm debating trying to DIY or just sending it to a shop where as said aboved I figured they'd charge about $150 to do it. They can afford to charge that since it averages out with some 15 minute installs and some 7 hour ones. The question is, 'Do ya feel lucky punk, do ya?'...normally when I ask myself that and say yes 7 hours later my head has a bump, my knuckles are bloody and my car is still broken :(

On the emissions stuff being that I'm in CA I have a storage spot in my garage where the stock air intake, pre-cat, etc will go to swap back in if needed for testing when it comes around again.

DP are alway a pain in the ass.

Just got my on a couple weeks ago. Also ebay bought. And did it go on easily, no!....But the idea is to do it yourself, make sure that it is done right. This includes buying new studs, nuts and gaskets and taking your time so you don't beat the car up in the process.

Take a deep breath every once in a while and don't worry about time. Just take each situation as a separate problem to solve.

I can't remember how many different socket and extension combinations I used in the job but it was a lot.

Also had a helluva time with the CAT nuts----I literally applied my foot (and tremendous force) to the wrench to get them off and my legs once squated around 500LBS...fortunately I didn't break the studs off.

Nevertheless, when I tried to mate the CAT to the DP it would not go because the heat shield over the CAT bumped up against the exhaust canal.

Don't know if anyone else has run into this problem??????
or if it's because my DP simply curves up too much but that was completely unexpected.
Have a Bonez hi-flow on the way which hopefully will connect right up to the DP. Didn't like the idea of attaching the CAT and all that weight to the DP without a bracket anyway so I'm hoping the weight reduction of the hi-flow will alleviate my concern.

TracyRX7---go ahead and give it a shot. Use lots of LW---that stuff really helps a lot. Be patient and allow for plenty of time. Keep the stock parts as you plan, make sure you raise the car safely. I use a ramp myself....just feel safer vs stands---there's less room but enough to do the job and easier on the car. Don't want my wife and kids cashing in on the policy just yet:).,
Work the nuts back and forth, don't be too aggressive---if you get them out a little and they tighten up, spray some LW and work it back in.
I thought the DP wouldn't be too much harder than the fuel filter and was completely mistaken.

Good luck!!!

TracyRX7...one other thing...I wouldn't just take it to any shop for this or anything at all. Rick's close to where you are, you may want to consider him.

Damn sounds like a nightmare you had there. But I have to say not all ebay parts were made alike. I am lucky my exhaust was already removed before I got the car because the bolts seem to stay in place. Well anyways read the threads and I used anti-seize to put my bolts on. Altother it took me about 15 min to install the downpipe. Holes lined up with precision, no alterations at all, so I am a happy man.

TSUDO DOWNPIPE ALL THE WAY!!!!!!

ps. what kind of bolts did you guys use, to install the part???

Downpipe install from hell #2:

So after reading this thread and doing some "recon" work (removed all of the intake hoses, checked out mainfold bolts, etc) I decided to send it in to a shop since they'll have exactly the right tools.

Three hours after they have the car up on the lift they call me, "The DP is on the mainfold now but it won't line up with the cat. Sorry it took so long but one of the bolts on the manifold was stripped. The next problem is the flange by the cat doesn't line up with the cat. We think by putting on some 8mm bolts instead of the 10mm we might be able to get it connected." ... "Sounds good to me go ahead."

An hour+ later..."We've pulled the entire cat off of the car and hooked it up to the DP and then we tried to remount but the cat wouldn't fit back onto the car, its too twisted. We've got the cat back on the car now and we're suggesting at this point that you pull the DP and get the flange removed and turned about 10 degrees so it hooks up."

So I'm picking up the DP to take it over to an exhaust shop to have the flange cut off and moved so it lines up :(

sounds like it pays to buy a slightly more expensive DP.. hopefully the HKS that I got will line up well, HKS are known for quality parts after all.

wow, that sucks! at least your not having to do all the work. what kind of dp is it?

Not certain, bought it used. I think it may be a Pettit (maybe this is why I don't see the downpipe listed for sale on Pettit's site anymore?).

From talking to my shop (they make their own downpipes) they've had whole batches come from their manufacturing like this (something probably gets lined up wrong on the machine that is doing the cutting/bending/welding and blam all of them wrong).

They had to return a whole batch of 50 and have the flange turned :( so this isn't the first time he's run into this problem.

As far as doing the work..I enjoy working on cars but you learn (either that or you can afford to have a choice) when its going to be enjoyable and when you're going to be cursing up a storm because you don't have a nice lift and all of the perfect tools to get the job done. Picture how long this could have taken me sliding around on my back under a car on jack stands without a second person to hold the cat/etc trying to line the stuff up.

Final result of my install: https://www.rx7club.com/showthread.p...hreadid=307954

Uhhh.. I just went to Pettit's site. Part EX-PE-GB198, 3" DP that replaces pre-cat. $299. That's where I got mine ages ago. Zero problems.

An aid is to replace the long stock precat studs that are in the turbo housing with shorter ones, N391-13-456 from mother mazda. Get 4. The DP will slide right over them. The short side radius of the DP makes the last stud difficult to thread the nut over, but you just move the dp out from the turbo, get the nut started, then move it on. Use split lock washers under the nuts to deal with oversized welds.

PB blaster rust remover is YOUR friend, as is running the car before the initial spray of PB blaster (allows it to get into the threads). I had my precat off the car before it was cold (but not before it stopped beating :) )

Just my $0.02. Pay a little more for the DP, avoid this mess!

Yeah I did more digging on the Pettit site later and found it listed (but too late to edit the post). As in my post above pointin to the Classifieds section thread it turned out to be the downpipe from the RX7Store downpipe/midpipe combo (so the DP may have never been fitted to the main-cat just as a combo to the cat-back).

You guys should always research on the part you are buying for fitment and quality. I got an old style PFS DP for cheap and it fit just fine without taking stud out. M2, Pettit and HKS are others that are good quality. I would not buy anything else. Saving $100 and spending 5 hrs dremeling the holes is not worth it.

I recently bought a used RB dual catback as well. It was a 45min job to install. I highly recommend you get a catback after the DP bc you'll be equally impressed. RB and M2 are quiet while others can be loud.

What you guys think about this combo dp and mp from rx7 store?
http://www.rx7store.net/index.asp?Pa...ROD&ProdID=596

The combo together fits just fine (from what I've been told by others). The DP by itself won't hook up to the stock main-cat (at least the one I have doesn't on my car as said above).

NOTE: RX7Store does not sell the DP by itself, just the MP (which may or may not be the same MP as with the combo) so it probably was never intended to be a bolt in replacement for the pre-cat.