Sherry

My pet '86 911 with B&B Tri Flow isn't passing the current CA emissions testing. My mechanic tried adjusting the oxygen sensors, building in cats and using fuel additive... it still isn't passing. Does anyone have any ideas short of putting a stock exhaust system back on (and losing the awesome sound?... to say nothing of the expense that involves.)

thanks,
Sherry

cmoss

did it use to pass?

if not, or if it's a new mod you may be stuck with removing it--till after the test.

btw this is why I stayed away from exhaust mods. Maybe others here have made them work?

Sherry

Hi Chris, thanks for the reply... yes it used to pass. I've had the car in CA since Dec 2000. It has always been an issue, but now it seems that we can't get it to pass at all. Haven't made new modifications. In fact, last time, we put special cats on (they weren't actually built for the exhaust system, so they needed to be removed after the test) but even those didn't work this time. I just hate the thought of losing my B&B Tri Flow and spending over $3K. It is such a great car, though. 86 911 turbo-style wide body... just awesome.

997for40

can you post the smog readings? an aftermarket muffler should not affect emissions in my opinion unless you have the complete exhaust system installed including headers.

did he check if the cat converter is still good? 02 sensor?

Sherry

I do have the complete exhaust system installed, including headers. I'll check whether I can get the smog readings to post and whether they've re-checked the cats. Thanks for the reply.

-Sherry

TT Oversteer

I'm confused as to what complete exhaust you have on your car. With headers and no cat your car will not pass smog. You should be able to find a complete stock exhaust for not a lot of money here or on pelican. Bolt on the stock system with a good cat, have a porsche specialist set your idle mixture (CO setting) and barring any other abnormalities your car should pass.

theiceman

putting on the stock system should work unless you have severely worn valve guides or seals and are just burning too much hdrocarbons.
Putting on the original exhaust is always a risk with thise damn brittle exhaust studs ... but if you have no choice , then you have no choice ..

BlackPearl

I use a local P-car specialty shop for smogging my SC (yes, it's easier than a Carrera with Motronic ... agreed). The local shop adjusts the mixture and checks the car before they go down to the smog-only station. Hint: M.O.T.T. I run a cat. bypass and rich fuel mix for track purposes. When I smog it, I install the cat and drive it for two or three days to get the crud/moisture out of the cat. I then re-install the Lambda/O2 sensor system, and have the shop "de-tune" before they take it in (usually timing and air/fuel ratios adjustments). The shop charges me around $250 for "adjustment, check, and certificate." Unless there are gross problems, they charge the same each time.

Now, after the certificate is in my hands, I "re-tune" the car for the track.

I would suggest calling a really good P-car shop in your area and discussing the issue with them. Sometime .... just sometimes ... shops will "rent" you a stock exhaust system as part of the fee for smogging your car. After the certificate is in your hand, they put back your modified system and return their "stock" system to the shelf. Of course, you'll pay for the labor of uninstalling/reinstalling your B&B exhaust system, but hey; you drive a modified Porsche. (Good tuner shops often have old, stock exhaust systems lying around that were removed from a racer conversion. Maybe you can find a stock unit that was pulled from a racer?) Did you by any chance save your old exhaust system?

Good luck!

Sherry

Thanks all for the advice. DM Motors in Palo Alto has my car and they've tried several things already. I have the B&B Tri Flow system with cats that they built in, but aren't sufficient for CA. DM motors put other cats on to try, and adjusted the oxygen sensors. They used fuel additives and drove through 3/4 of a tank. The results got better, but not good enough to take to the test-only station. I'm at the point where I think I'm going to need to put a standard exhaust system on. DM motors used to be an exceptional shop, but has since changed hands and the new owners just don't have the knowledge. Anyone have a suggestion for a better shop in the bay area?... perhaps one with a stock exhaust system for "rent"?

thanks,
Sherry

997for40

sherry, i would talk to tony at heyer performance in mountain view. he works on these air cooled p-cars alot. as far as DM motors owned by ross now, they're a capable shop, brought my bmw 635 euro when it didn't pass smog but they are not p-car exclusive. i guess the final word is putting the stock exhaust system back on and just re-install the b&b muffler and cat bypass after you pass , keep the headers stock like what i did with my 911. the cat bypass & sport muffler is enough to produce a sweet exhaust note in my opinion and the bypass is easy to remove when its time for smog.

9114LIFE

I would suggest David Modderman (www.modderman.com), he has been working on my family's P-cars for many many years.

I highly recommend him and I believe he has a Smog station to test if the car will pass, but not the roller kind...

Sherry

Thanks 997for40 and 9114LIFE for the recommendations. I'll check them out.

-Sher

Marty916

I've had good experineces with RMG in Sunnyvale and CT Automotive in Campbell. CT uses a smog test guy a block from their shop who knows 911's and has the roller type of tester. Just had mine done there last weekend. Good luck!

Sherry

Thanks Marty916. I'll check them out... is the test guy that CT uses a test-only station?

rusnak

Quite a lot of 3.2 911s are not passing now.

My theory is that the new gas or something is causing them to need adjusting.

If you can post your results, maybe you can get some more insight from the board. The most obvious thing is to check for vacuum leaks and then make sure that the O2 sensor is going into control mode. I don't know what you mean by "adjusted the o2 sensor".

You can also try checking your fuel pressure and checking your CO mixture. I had trouble passing my 3.2 until I checked the CO mixture. Last but not least, you might remove your spark plugs and try to ascertain whether or not one of your injectors is plugged.

Oh yeah....don't touch the exhaust system until it is the very last thing you have tried. But if you do remove it and decide you don't want it...I'll buy it from ya!