Exhaust Round Two.. help me sort this biz... - e30 m3 s52 obd1 swap

[r4esh]

Alrighty guys, I "finished" my s52 obd1 swap into my e30 m3 not that long ago. The car has been running for months, but I have very little time to work on it. As of now I can't get it to pass Arizona emissions (which are pretty lenient).

The right now setup is:
Aftermarket headers - not sure the brand. They are heat wrapped. -> DUEL 2'' piping -> Custom 2'' X-pipe with O2 sensor -> Duel 2'' pipes -> Stock OBD2 Cat -> Duel 2'' Pipes -> duel in duel out Aftermarket muffler - not sure on the brand.

I just used the obd2 Cat and aftermarket muffler that came on the 97 m3 car that we pulled the motor and such from. All in all the setup sounds pretty decent. With those headers and everything it has a nice beafy sound. I will post a clip later.

So here's the issue - The car wont pass emissions. I have all brand new sensors. Brand new cam, crank, iridium plugs, and new O2 sensor (which for the o2 sensor I DID have to cut and extend using wire bungs, shouldn't be an issue though). I'm assuming my issue is the used / failed catalytic converter. Thoughts? (also I ran "heat" in the fuel and drove it for at least an hour before running emissions).

Other notes: The car is tuned by TRM for my setup (3.5'' maf, s50 intake, 91 octane). The car runs / pulls and idles awesome and doesn't smell rich ever!

If it IS my catalytic converter that is the issue what would you all suggest? Replace with cheaper aftermarket that flows better? (this would require re-doing / having more custom exhaust work done). Or find another stock OBD2 cat? The used cat I'm using was out in the rain for a few months... I have driven it a LOT though since we got her up and running.

My OTHER Issue: My aftermarket stainless headers don't fit this swap at all... I currently have 5, yes FIVE THICK washers on the passenger side engine mount in order to have the headers clear the subframe without resting on it. I'm ALSO using custom sway bar spacers to lower that for clearance... as well as Treehouse Racing Eyeball arms.... yeahhhhhh... So I tried "massaging" the headers with an impact hammer... bad idea... I put a small hole less than the size of a dime in it. FML!

I think I need a new Cat setup to pass emissions and I need to have someone manipulate / repair my headers to fit the swap. Basically practically re-doing my entire exhaust setup... so I figured I'd post and see what your thoughts were.

Pics:

[CoreyZ]

They look like Racelands, but I can't tell. I have the same headers, and yeah, fitment sucks.

Do you have any paperwork from your last test?

[Adrian_Visser]

Those aren't racelands, I have racelands and they fit even worse than that. The secondaries and flanges on the racelands are Facking huge, those are itty bitty little pipes you got there. I have heard that the v2.0 racelands fit a lot better and most of the swaybar/subframe clearance issues have been taken care of. My main issue is just that the flanges themselves are so damn low to the ground that I scrape every speed bump I lay eyes on.

[brody]

If you have a infrared heat gun check the temperature of the exhaust pre and post cats. If they are working the temp should be a few hundred degrees hotter.

[scottinAZ]

I would be concerned with your cat being shit. Another concern I have is the o2 sensor being so far back that it isnt as hot as it should be. this can cause bad readings, and also poor emissions. Judging by the size of the cats, they appear pitifully small, so may not be working at peak efficiency any longer

What number did you fail on? CO/HC/NOx? makes it easier to figure what is off if we know what the numbers were.

Is the stock ECU being run in this car or is it Megasquirt or other? OBD2 uses both pre and post cat o2 sensors, so if factory ecu, and not tuned out, you will need that input as well.

[cormier]

^^ he is obd1
In AZ do you guys have a 2 speed idle test instead of full etest if you can't get a tach signal? A lot of testers in my area are willing to do this of you know them etc and it's almost a guaranteed pass

Header wise maybe shorty headers with custom downpipe? If youre getting it fabbed anyways that way you can get a nice fit :)

[scottinAZ]

^^ he is obd1
In AZ do you guys have a 2 speed idle test instead of full etest if you can't get a tach signal? A lot of testers in my area are willing to do this of you know them etc and it's almost a guaranteed pass

Header wise maybe shorty headers with custom downpipe? If youre getting it fabbed anyways that way you can get a nice fit :)

Ok, For some reason I was thinking OBD2.

AZ has state run inspection stations, so there is no "knowing someone" here :(

testing for this year car is done on a dyno where they run a simulated road. goes from about 1st gear through 3rd-4th up to about 45 mph. everything is tested.

[Jalves619]

Those cats came directly off of the 97 M3 that the motor came from. The car was just over the limit at speed, but failed horribly at idle. I think it was both CO & HC but I'm not positive on that one.

[CoreyZ]

Well, your O2 sensor isn't plugged in :D

Given those are used cats, they could just be bad. What's the mileage?

If those are Racelands - they're routed the same, at least, and the collectors appear to be larger than the 2" piping aft of it - there should be O2 sensor bungs in each one. You could try moving the O2 sensor up to one of those ports too.

[scottinAZ]

Those cats came directly off of the 97 M3 that the motor came from. The car was just over the limit at speed, but failed horribly at idle. I think it was both CO & HC but I'm not positive on that one.

Goes back to the OBD2 taking readings Pre and Post cat, can tune for emissions that way, getting the cats to do more (or appear so) with less cat there.

Being OBD1, there may not be enough mass there to work without the other sensors.

I would look seriously at new cats... Even getting a set of OBD1 cats may be enough to get you through.

[r4esh]

Thanks for the responses. I'll post my Emissions score later today when I'm home. There were 130k miles on the engine / cats when I swapped them over. I'm going to see on costs of getting my stainless headers "re-worked" to fit the clearance, but if its too costly I'll just get different headers (what a pain). And yeah I am OBD1.

Looks like I should get some good cats / resonators - what would you all recommend?

A buddy of mine recommended I get 2 of these: LINK

[Jalves619]

1. Get rid of the spacers
2. Bend the headers with copious amounts of heat, or get someone to do pie cuts and reweld to clear subframe.
CLICK HERE
or
Buy another set of headers.
CLICK HERE
3. Put in new cats while hopefully getting some interchangeable test pipes made, or at least make them easily replaceable. With cheapo cats you get what you pay for.
4. Drive it. It's so close.

[e30rapidic]

Bueller......

Well, your O2 sensor isn't plugged in :D

And those are definitely not Racelands....

[Adrian_Visser]

Okay I forgot there are two types of Raceland headers, those do look kind of like the two piece ones. Jeez my one piece ones have such shitty clearance it isn't even funny. There is probably two inches between the pipes and the body at the flanges.

Btw raceland uses oddball flanges for anyone reading this thread thinking about buying a set, take them to a machine shop before you get them installed and get some matching flanges made. They are a 61 mm hole distance.

[CoreyZ]

The only reason I say those are racelands are the routing of the piping, it's diameter which appears to be bigger than the 2" pipe following it, and the fitment. Mine fit the exact same. One of them is nearly hitting the cab, right?