Failed Emissions

FenderGuy · 10:17 AM

Ok failed the CO test. anycare to comment on the numbers?

Its funny how I failed? And yet the tech looking at my car had to get 5 other people to look at the equipment, says he never checked out a Porsche

On a side note I had a blast driving home from Glendale

bonaturtle · 09-13-2006, 10:15 AM

I failed mine too, 4x legal limit on HC's and double the limit on CO2. I'm thinking I have a bad O2 sensor, as my exhaust pipe is full of soot.

I was also thinking the cat, but the O2 is a much more simple fix. If that does the job cool, if not, then I'll attack the cat.

Jeff · 09-13-2006, 12:42 PM

Frank, Do you have the cat installed? Did you get the car nice and hot before you tested it? I have an extra cat if you need to borrow it (well once LeeH takes it off his car). Lee's didn't pass emmisions until he put it on. Not sure what his numbers were but you might want to contact him and compare.

stlrj · 09-13-2006, 04:52 PM

Wouldn't it be a better idea to have your mixture set to spec and pretested before you take it in again? That way you wouldn't need to spend any money on parts that you don't need.

Joe

sal · sal's Garage

I agree with Joe. Don't spend money on things that may not solve the problem. I recently failed my smog check so I ran out and bought a the CO sensor and replace it. Well that helped a little but it still did not pass. The tech said it was running rich to adjust the mixture. The problem was how much to turn the adjustment screw? In California we have what is called test only stations which are not allowed to do any adjustments to cars so we waited till nobody was around and I took the allen wrench and tweaked it a bit got it close to passing even a bit lean. The final move to get it passing was the tech pulled the vacuum advance hose from distributor. Prior to doing the smog test I was ready to replace the cat(when I shake it sounds like a large baby rattle), CO sensor (20k since last replaced) and any other part that I thought could help the car pass smog. I am glad the tech helped me. I think now an adjustment was all I needed to pass.

HarryD · 09-13-2006, 05:52 PM

Check this thread for some ideas: Emissions failed & Octane question

ruf-porsche · ruf-porsche's Garage

Check this thread, especially the info on the stuck injector

Whooooo Hoo

Whooo Hooo

FenderGuy · 09-13-2006, 08:45 PM

wow finally get home, it was a long day i am giving the 911 a rest tomorrow .....ok prior to testing I let the engine warm up for at least 7 minutes, seems to take forever for the oil pressure need to go on the white...drove it to the station nice and warm and failed..the tech said the same thing to me "running rich to adjust the mixture " BTW i forgot to mention the person who thought the engine was in the front

I called Don Jackson and Stuttgart to schedule a valve adjustment and oil change just for own peace, they both said a adjustment could easily be made to pass emissions....Jacksons busy till next thursday and stuttgart has room tuesday....

my new muffler pieces are coming in anyways, i'll put them on and let the CO shine...j/k

stlrj · 09-14-2006, 04:09 AM

Frank,

You really need to pick up one of those T-allen tools for adjusting the mixture yourself. It only takes a few seconds.

Joe

bonaturtle · 09-14-2006, 05:16 AM

what is this t-allen tool?

FenderGuy · 09-14-2006, 06:02 AM

Quote:

Originally posted by stlrj
Frank,

You really need to pick up one of those T-allen tools for adjusting the mixture yourself. It only takes a few seconds.

Joe

Yeah I know, I dont want to become dependent on the shops...rather do the small things myself....

FenderGuy · 09-14-2006, 06:07 AM

Quote:

Originally posted by bonaturtle
what is this t-allen tool?

http://www.pelicanparts.com/cgi-bin/ksearch/PEL_search.cgi?command=show_part_page&please_wait=N&make=POR&model=911M&section=FULcis&page=16&bookmark=2&part_number=UN-120-1334

check that look link ...its under CIS Fuel Enrichment Wrench its a deal for $5.35

also get waynes book, which i should be reading

Jeff · 09-14-2006, 06:22 AM

I agree with leaning the mixture, LeeH and I did this to his car so it would pass (also installed a cat). If you do this, write down how far you turned the mixture screw so you can put it back. You will probably have to adjust the idle up to keep it running (once again write down how far you turn the srew).

You said you drove it about 7 minutes before testing. I always drive mine at least 15 minutes HARD before testing.

I'll PM my phone # if need more info.

FenderGuy · 09-14-2006, 06:27 AM

Quote:

Originally posted by C U L8R
I agree with leaning the mixture, LeeH and I did this to his car so it would pass (also installed a cat). If you do this, write down how far you turned the mixture screw so you can put it back. You will probably have to adjust the idle up to keep it running (once again write down how far you turn the srew).

You said you drove it about 7 minutes before testing. I always drive mine at least 15 minutes HARD before testing.

I'll PM my phone # if need more info.

nope 7 minutes to let it warm up and then drove it for another 15 minutes

stlrj · 09-14-2006, 06:38 AM

After you get it to pass, put your nose to your tailpipe briefly and memorize that smell so you can set it like that two years from now when you need to smog again.

Joe

LeeH · 09-14-2006, 07:36 AM

Frank,

My car failed the test at 4.11% under load. The idle was fine the first time (.92%). Like Jeff said, we put on the cat, leaned it, got it real hot and it was practically putting out pure oxygen on the second test. .02% CO! I'm sure that's way too lean for this car. Now I'm trying to find an exhaust gas analyzer so I can adjust it properly.

quattrorunner · quattrorunner's Garage

You don't even need that T tool. It's an allen wrench, everyone has a set. It's 3mm I think.

john70t · 09-14-2006, 08:26 AM

You might want to buy a relatively expensive exhaust-gas analyzer to set it properly, or just pay for a few more tests at the shop.
The Gunson model is popular, do a google search also.

The t-handle can be found a lot of places like http://www.autotech.com/prod_engine_tools.htm .
The adjusting screw is very sensitive. Start with 1/16ths turns, remove the wrench(!) and rev it between checks.

ruf-porsche · ruf-porsche's Garage

Did they test the car on a Dyno? Here in the Windy City, they test the cars on a dyno to see the emission not at just idle but also up to 50 mph.

Only cars older than 1975 are exempt from the dyno.

FenderGuy · 09-14-2006, 08:54 AM

Jeff and Lee

do you guys want to get together over the weekend if you have time?
to play around the mixture? I have no clue what to do when changingthe mixture, rather have some experience hands glide through the process.