If that’s a problem you must be living a pretty good life, lol ...

 

Or take my approach. My cat is loosely taped up and stowed in the attic. When I finally decide to sell the car, the OE cat will go back on, and my BHR / HJS pipe will be sold along with several other performance parts.

 

I shoved a small flashlight and it doesn't seem that clogged, hmm, I will have to verify further. If I can't find a problem, I will put it up for sale.

Anyway, here are some pics of the pipe installed since I went back to the exhaust shop to fix another small hiccup:

At some point last week, I noticed a small chirp coming from the rear of the car. It is particularly noticeable if I drop the idle. I eventually got under the car to have a look, and noticed that the hanger and the frame are rubbing against each other(the area in the yellow circle), hence the chirp. The exhaust shop did have to bend the hanger a little bit so it will fit in the rubber boot, so they bent it again so it would stop rubbing against the frame. Sure enough, the chirp is now gone.

Seems like the hanger is not very S2-friendly. If you look at the part in the red circle, you can see the boot has to be moved so the hanger would go in the boot, leaving part of the other hanger protruding. Is that a problem you have, Steve?

 

Actually, yes. I had the same chirp the first time I installed it. I have a 3 pound hammer and anvil, so I just "adjusted" it a bit and reinstalled.

 

It’s the same S1 or S2

 

The shop has a blowtorch, so they just heated it and bent it.

I guess pounding works too, but I have misplaced my hammer. It's probably too small for this kinda work anyway.

But my hanger is just straight up too short. I can understand that it may have got bent a little bit during transportation, but it's kinda strange that this hanger is just too short.

It's not a big deal, but worth mentioning.

 

That’s the difference between what you read (or not) on the internet vs reality. I had to make the same mod on someone else’s S1. It looks exactly the same.

 

We all have different tolerances for massaging aftermarket parts to make them fit. I always assume exhaust parts will require adjustment, so I go into it with tools in hand. Putting a little bend in it was no big deal to me.

Hell, you should have seen the crap I had to go through to get the Roadster Sport midpipe to hook up to the Racing Beat header and muffler on my Miata. Let's just say there are plenty of hose clamps and zip ties involved. The BHR one on the 8 was cake compared to that hot mess.

 

Yeah, pretty much that just goes with the terrotory

 

I can't complain too much then. BHR midpipe went on without too much incident. There was no fitment issue other than that hanger, which is trivial.

 

Bump.

My 09 is due for emissions test and I need to find a solution for a new cat. Currently I'm running a gutted OEM cat with a CEL. Questions :

1. Can an HJS cat be welded into the OEM midpipe or do I need to swap out the whole midpipe?
2. What is the correct HJS cat? Is 90 95 0182 still the best option?
3. What is the solution for the rear O2 sensor? Doesn't look like the HJS cats have the bung in the middle of the cat like the OEM. Can I have an exhaust shop install it immediately downstream from the cat?
4. Any other options been found besides HJS?

Thanks for any help!

 

If you want to stay with the OE midpipe for the least cost then this one will be a better fit; HJS-Nr. 90 95 0072 with a 63.5mm inlet/outlet. Probably be a little less expensive too. The other one will work, but the 70.5mm inlet/outlet will need some adapter work. It’s really your call.

the OE catalyst section is actually two cats with the second O2 sensor between them. The theory is that if the front cat goes bad the O2 sensor reads that and provides a CEL code, but the rear cat still provides emission compliance.

so with an aftermarket cat you just need to add an O2 bung in the pipe after the cat for the second sensor. Any exhaust shop can handle that.

Which on the OE cat you might have been able to just bust out the front cat section and move the O2 sensor behind the second cat & plug the other bung and possibly could still have a functioning OE cat.

 

Dang that's a great idea, wish I would have known that before I completely gutted it. Thanks for the great info though Team, I'll probably go with the one you recommended. While I'd love to get back into it I haven't done any track days in years so for now I just need something for daily driving.

 

One more question, where can I purchase the HJS cat? Google searches haven't turned up any options. Do I need to contact HJS directly?

 

You might have to buy it from an overseas distributor. That’s where I had bought both of mine (Germany) before they tried to open a US site, but I think it closed down several years ago. Probably should just contact them and ask. I always had good contact response with them, but that was 8 or 9 years ago. I still have my big 3” 450hp ultra-flow race cat from them, but am holding onto it for now.

 

Turbo Zentrum is where I got my HJS cat. Alternatively you could contact HJS in Germany yourself but Turbo Zentrum's price isn't bad.

 

This is the only company their website lists as a USA partner. They have a lot of specific HJS exhaust options listed for high end cars, but not the general catalysts you need. They might be able to get it for you with a regular shipment though. You’d just have to ask:

https://www.fabspeed.com

you can’t buy direct from HJS. I only suggested contacting them for a possible USA supplier name.

.

 

Thanks all for the help. I was able to purchase the HJS 90 95 0072 cat through fabspeed for $430 shipped. They don't stock them so it's a month lead time to get it from Germany
​​​​​

 

Doesn’t seem like a bad price really.

 

The HJS-Nr. 90 95 0182 I used was easy to install. The shop flared the bells slightly, slip fit the pipe inside, then tack welded it on the car. That is a simpler method than welding the same diameter pipe, which means lower installation cost.

Yeah. Mine cost around twice that. Of course, mine was also an HD unit, which I wanted for track work.

 

With a mostly stock car and midpipe it’s fine and unless the shop is incompetent; will be installed without issue.

 

Going with an HJS but here is a stupid question before I order...Would a 200 cell actually last longer than a 100 cell. At first you would think the better flow of the 100 cell would last longer. But double the cells in the 200 cell would obviously be cleaner. Which one lasts longer street driven?

 

If it’s a street car then just buy the large 200 cpi one and stop trying to overthink everything.

 

im about to pull the trigger on the latest HJS 90 95 0069 for a track prep car.
as TeamRX8 suggested, pick the cat with the most flow for 100 cpi. 0069 is rated for 3000 ccm.

My question is: would this cat be enough if I premix 250ml per tank for a HPDE?
Should I reduce my premix if cat is added?

 

you could put v-band or other clamps on both sides of the cat converter and then have a straight pipe piece made to swap in/out with it for that tank of fuel/premix.
.