Cant f*&<king pass emmissions with my S52 swap car

[Pipes]

DAMMIT! I've now tried 4 times and I keep failing the low idle. I have changed the chip back to factory, installed new plugs, oil change, and even added denatured alcohol to the fuel. This morning I drove it for 30 minutes and got it HOT right before the test. with all those changes and getting it REALLY HOT, the HC at cruise was excellent: limit is 400, my result was 128. But the idle emissions limit is 400 and mine was 563 (was 598 last time).
Specs: 98 S52 w/OBD1. Supersprint headers to 2.5 system w/ magnaflow cat and vibrant resonator and muffler. It's running great- 240hp at the wheels.
Thoughts? Leaky injector? Or do I need a better cat? My tabs expire in October but the clock is ticking....

[bimmerteck]

Look for vacuum leaks letting in unmetered air after the MAF.

[e30austin]

I would go back to a factory cat or get a new universal cat. How old is your current one?

I have a full OBD2 midsection with cats I would let go if you are interested...

[Pipes]

The cat is 2 months old. But it is a "performance" cat. Now I really wish I'd had it tested with the old exhaust before swapping in the new system.
And wouldn't unmetered air make emissions cleaner...?

[e30austin]

Interesting. I would inspect all your vacuum hoses then. Does the car run or do anything weird at idle?

[BraveUlysses]

You can apply for an exemption, but it could be tough with the aftermarket stuff on there.

http://www.emissiontestwa.com/e/faq.aspx#15

The vehicle owner may request a waiver at any Applus Test Station if an Ecology Authorized Emission Specialist (AES) has repaired the vehicle after the initial test failure.

Vehicles with missing or tampered emission control equipment will not be waived.

You will need to provide itemized receipts that show that at least $150 was spent on emission diagnosis/repairs of the test failure. You will also need the failed test report signed by the AES. Refer to the brochure given to you when your vehicle failed for additional information.

[Pipes]

No exemption allowed on a swap car.
The idle seems fine. One thing I haven't done is to put in a new fuel filter. THink that would have any effect?

[bimmerteck]

And wouldn't unmetered air make emissions cleaner...?

No, unmetered air skews the O2 sensor readings so the vehicle thinks the engine is running lean running lean so the DME lengthens the PW of the fuel injectors(by adjusting fuel trim). This puts more fuel in the cylinder than is necessary for a clean burn which is then exhausted as excess HC. Unmetered air leaking from a location behind the closed throttle plate will effect emissions most at idle due to the high manifold vacuum at idle.

[10Toes]

DAMMIT! I've now tried 4 times and I keep failing the low idle. I have changed the chip back to factory, installed new plugs, oil change, and even added denatured alcohol to the fuel. This morning I drove it for 30 minutes and got it HOT right before the test. with all those changes and getting it REALLY HOT, the HC at cruise was excellent: limit is 400, my result was 128. But the idle emissions limit is 400 and mine was 563 (was 598 last time).
Specs: 98 S52 w/OBD1. Supersprint headers to 2.5 system w/ magnaflow cat and vibrant resonator and muffler. It's running great- 240hp at the wheels.
Thoughts? Leaky injector? Or do I need a better cat? My tabs expire in October but the clock is ticking....

Didn't know BMW made a chip for M50b32

[Pipes]

Thanks all I will look for a vacuum leak after the throttle body. I hope it's obvious-- I've already spent $60 for tests so far :(

[eurotrash]

Get a can of starter fluid and start spraying the intake after the maf. If the idle goes up you know u have a leak in that areA

[Den_k321]

i would almost let you borrow my exhaust, but its custom... and if its idle low, why dont you just adjust your throttle cable to idle higher?

[Reckless_Havoc]

High HC at idle is common when there's a fuel injection problem. I had a similar issue on an M20 and had the injectors rebuilt. Problem solved.

I used a high performance cat on my S50 swap (about the size of a large can of coke) and it passed emission np. Almost didn't pass the visual because the old bag didn't believe it was a cat.

Good luck!

[Pipes]

Woohoo! Passed, finally!

Couldn't find a vacuum leak. Put in a new fuel filter, tried again. No dice. Tabs expired in October. I was driving around for November on expired plates. Just before Thanksgiving I was perusing the classifieds as I seem to do on a twice daily basis, saw an ad for a cat, and decided to try adding in a second cat inline after the first. Cat was $100, installed it for $80 yesterday, went to the emissions testing station this morning. Check out the before & after results!

[Pipes]

The cat is a Walker 80301. It's CA Legal. Only downside is that it is 2" in and 2" out so I had the shop open it up to fit my 2.5" system.