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Failed Calif Smog Test...need advice!!
1988 Porsche 911 just failed the California Smog test with the following numbers:
15mph: HC (Max 121, Ave 31, Meas 186) CO (Max 0.76, Ave 0.10, Meas 0.56) NO (Max 807, Ave 237, Meas 1671) 25mph: HC (Max 96, Ave 20, Meas 106) CO (Max 0.65, Ave 0.09, Meas 0.34) NO (Max 746, Ave 199, Meas 878) The car has 95K miles and runs well. White smoke only comes out in the morning but it goes away after couple miles. The exhaust does smell a little all the time, but no smoke at all after the engine is warmed up. Questions: 1. I found a bottle of $6.99 fuel system cleaner "CRC Guaranteed to Pass Emissions Test Formula" from Kragen, and it's supposed to help "reduce CO, NO & emissions". Does anyone recommend that I try that out in order to pass the California smog test? Would that potentially damage the engine of the 911? Should I even give that a shot? 2. If I need to get someone to fix the car up so that the car can pass the smog test, does anyone know of any good mechanics in the San Francisco bay area that can help me fix up the car? Any idea on what needs to be fixed or how much it will run? 3. Any other suggestions/advice? Thanks, Andy |
Move to rural Nevada.
No, just kidding. |
With those NOx numbers (which are *very* high) your catalytic converter is dead almost for sure.
This is an example of where the smog test may actually help you and your car. Your cat is dead, and there is a good chance that it is clogged, too (I was at a shop yesterday looking at a melted down cat off a Carrera). Your car will probably run a lot better with a new cat. I'd stick a new cat on it, and pre-test it again to see what the numbers are. |
when was the last time you had a tune up? did you just get the car?
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Did you get notified to take it to a smog test only station?
If you did, you are in luck. There's a program in California that will pay for up to $500 worth of repairs on your car (after you pay the first $100). If it is your cat (and I think it is) that $500 will come in real handy, especially if you need an O2 sensor too. The program is good only if you are mandated to take your car to a test only station and it fails. |
It was actually my brother's car but he moved out of the area and decided to give the car to me. The last tune up was probably from a while back, maybe 15k or 30k miles ago? :eek:
Any idea roughly how much it will cost to replace the Catalytic Converter? Would that help lower the HC as well? |
Andy,
I just went through the same thing you did about six months ago with very similar numbers, but I knew mine was going to fail because I had a by-pass pipe instead of a cat conv(I bought the car out of state). I installed a used cat conv bought from another Pelicanite and passed with flying colors. I would check the classifieds of this website for a used OEM. I got mine for about $100. You don't even want to know what a brand new OEM cat costs. Just a word of caution, find out how many miles are on the cat and make sure to see pictures of the honeycomb-looking screen on one end to make sure it is not damaged or clogged. PM me if you have additional questions. Good luck |
The way to prove its your cat is to drill a hole upstream of the cat and insert the emissions probe. Take readings before and after the cat. I agree the numbers will show your cat is dead. A new cat will reduce all three, including HC. You should expect less than .05%CO, and below 10ppm of HC. Many times the numbers will actually read 0.
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I wish I had a brother who would give me a nice Carrera.
Seriously though, when you fail big time on NOx and fail HC too, you're in trouble. That's because when you lean it out to fix the HC, your NOx will go up. Possibly your ignition timing has been advanced. That would increase your NOx output, and sometime HC, so do a basic tuneup first. Maybe try new plugs and check the ignition timing and mixture, otherwise you may need a new converter. Regards, Jerry Kroeger Regards, Jerry Kroeger 15mph: HC (Max 121, Ave 31, Meas 186) CO (Max 0.76, Ave 0.10, Meas 0.56) NO (Max 807, Ave 237, Meas 1671) 25mph: HC (Max 96, Ave 20, Meas 106) CO (Max 0.65, Ave 0.09, Meas 0.34) NO (Max 746, Ave 199, Meas 878) |
easier yet is just pull the cat and look at it, an exhausted cat will be almost empty, a good cat is full of the cat "stuff"
where are you located? jim |
Where in the Bay Area are you, because there are quite a few good shops down there.
If you're cat is bad, you can purchase a used one anywhere from $100-300. As for a new one, I've seen aftermarket ones for around $500, but you can always just cut yours out, and weld in a new one. It doesn't meet the letter of the law, but it will pass. Sounds like you need a tune up too. |
no kidding on the good brother! check some of the local salvage yards for 911's. i think they will have some used ones.
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In Northern California, check PartsHeaven (Hayward) or EASY (Emeryville). If PartsHeaven, ask for Spencer - tell him Steve sent you. Good guy (he just moved from EASY down to PartsHeaven).
Good luck and tell us how it works out. |
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yep, it is illegal to sell a used cat.
Not sure if that applies to individuals or just companies, but salvage yards won't even talk about it. |
Even without a CAT, a 3.2 will run fairly clean. The NOx number is excessively
high. As mentioned above, an ignition timing which is too advanced, e.g. a bad performance chip, will cause this. A bad plug, air leak, or wires can cause HC problems. You really need to go to a good Porsche repair shop and have some checking done. Good Luck Loren '88 3.2 |
My numbers were off the chart even more than that--even with a fairly new CAT. Of course you never do a smog check on these in hot weather or you're screwed.
What you can do is set the fuel quality switch to richen it up a bit. Mine is chipped as well, so it was running lean. The fuel quality switch is on the DME unit beneath the seat. Do a search on Fuel quality switch and you'll find it. Consult Bentley as well. I also replaced my O2 sensor. Make the guy at Pep Boys or autozone go through and look for a 3 wire O2 sensor. A 1980s or 90s Euro car ought to do it. A good guy will find one for you. You'll have to splice it into the other wiring (2 whites and a black), but it'll only be 50 bucks instead of 200 for an original one with the connector. Pour a couple of Octane boosters in there as well. After all that your CO will barely pass you, but you'll get the NOX numbers down which is being caused by a very lean condition. I think my engine is basically toast and that is why I had so much trouble. |
Andy,
it is hard to tell what is wrong without more info about your car. I would start with checking your timing. Fuel injectors could be clogged and leaking some fuel. Getting a new CAT and testing very soon will let you pass the smog but I don't think you want to replace CAT every two year if something else is wrong. I would do a basic tuneup first before changing CAT or O2 sensor. It is good for your car performance anyways. To do a quick visual on CAT, take your muffler off, just three bolts 13mm socket, and look at the honeycomb in your CAT. If the honeycomb structure is clogged or melted in the center, you need a new CAT. Before next check, use very high octane fuel and take it to the shop on cold morning. I have limited access to dyno at local referee and my 88 motor will pass without CAT present. If you futher help give me a call. 925-292-5200 -steve |
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Here's what you need to do: - Check the car on the exhaust scope (baseline) - Change plugs - Change plug wires - Change cap/rotor - Change oil - Adjust the valves - Replace O2 Sensor - Check the car on the exhaust scope (measure improvement) If little improvement: - Run compression check - Run leakdown test - Check for vacuum leaks - Replace CAT -Wayne |
yea, what wayne said. plus i always include a new air cleaner. ( i never show myself at a smog station without brand new motor oil.)
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Did you drive the car around prior to taking it in for the smog check? In Illinois they advise you to drive the car for at least ten miles before bringing it in for a smog test. A cold engine will be polluting more than an engine that is at operating temperature. Just driving a couple of miles does not warm up an engine.
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Andy, maybe someone up by you, in the local porsche club, has a good CAT and a stock chip you can use for testing. Ofcourse after a tune up, wires,cap,rotor,vavle adjust,air filter,new oil and filter,etc., like others have said before. Just an Idea. Mark
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I have a complete exhaust system and a stock chip you can borrow but I live near Sacramento. PM me if needed
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84toy Thanks,I knew that might work. I live too far away to get the same stuff to him. I hope it helps him. 84toy do you get to ride your LT very often. I love the ad on TV with the guy and his wife scraping the payment around the corners while driving the K1200LT in the mountains. Good stuff Mark
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TUNE UP TUNE UP Valve adjustment Injector Cleaner Cat
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WARNING: A Federal fine of up to $2,500.00 can be assessed for removing or tampering with a catalytic converter. Texas State Fines can be up to $25,000.00 for removing or tampering with a catalytic converter. Most States now have individual fines for those who would remove or tamper with Catalytic Converters. |
I spent $400 for a repair shop to put in a new O2 sensor, and I just got it smog checked again and it passed! It barely passed though but it did!
Thanks for all your suggestions and help! Andy |
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You're very fortunate to have recieved the car from your brother, now you just have to make sure you maintain it properly. An '88 911 is an awesome car. Make sure you get the tune-up, valve adjustment, etc. and keep track of the records. |
Just curious - how much did the O2 sensor cost? $400 sounds a little steep for the job, unless of course diagnostic time was included. If you plan on keeping the car, I would suggest Wayne's 101 Projects available through our host. You could've easily done that job yourself and saved a few bucks. Good luck.
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I was gonna say check the O2 sensor. I had a similar problem. I tried messing with the DME fuel switch and did two Smog pre tests. Finally I just took it to my mechanic and it turned out the O2 sensor wasn't plugged in all the way.:rolleyes: My wrench leaned it out a tad and it passed. Spend the cash and get a tune up, it sounds like it needs one bad.
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The part itself (O2 sensor) was $175, but they charged me $180 for the labor(installation). No other diagnostics whatsoever. In retrospect, I think the price's pretty steep. Unfortunately I don't know how to work on cars so I couldn't put it in myself.
Well, I'm glad that it passed the smog test but I guess I'd better get a tune up and starting getting the regular maintenance on the car, as suggested by so many. I'm fortunate to receive this car from my brother but I really hope someone can recommend a good reasonably-affordable/honest auto shop in the SF bay area(SF/Peninsula) for me so that I can afford maintaining the car. :p Any recommendation for an auto shop for the following work on the '88 carrera: - tuneup (how much does it normally run for minor/major tuneup?) - convertible top doesn't operate - electrical repair/diagnostics (windshield wiper doesn't work well and rear mirror control doesn't work)...wiring problem Thanks for all the help/info! Andy |
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$180 bucks just to screw out a 02 sensor and screw back in a new one. If they had the right tool to remove and replace an 02 sensor it shouldn't have taken them more than 30 minutes (time to put it on the lift, time to take it off the lift) to replace the 02 sensor that works out to $360 per hour. Learn something about taking care of your car or learn about being taken to the cleaner every time you need to bring it in. |
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My valve adjustment plus a bunch of small things cost me $300-$400 with labor and parts. This valve adjustment is done every 15k miles without fail. I had mine done at RMG and Bob let me watch the whole procedure and tried his best to actually show me how to do it myself. In terms of the other repairs, I highly recommend that you buy the book "101 Projects for your Porsche 911". This book is available here at Pelican Parts. Make sure you buy the one *from* Pelican since it includes a CD, the Amazon.com version does not. Even if you do not do the repairs yourself, this book will help you immensely in understanding the problem, the fix, and the possible expense involved. As for mechanics, RMG in Sunnyvale is good, I hear Modderman in Mtn. View is also good. The Bay Area has a ton of very talented Porsche mechanics. |
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