rnixon

My '93 GTS should finally be arriving at the end of next week. I'm planning on doing the following before attempting to get it smogged:

- Air filter
- Smog pump filter
- Spark plugs
- Good drive

Is there anything else that it would be sensible to do before the first California test?

Thanks,

Roger

polecat702

oil & filter change, fresh tank of premium gas.

1989porsche928

It should not have a problem. I am sure you have the stock intake tubes. I had trouble in the past in between throwing them away and buying new ones.

BC

Grab your ankles and...

It should be okay. They have been recently very "aggressive" with random changes to what they WANT your car to smog at instead of where it was actually manufactured.

That said, it really depends on the "**** list" of cars CA doesn't want on the road any more. The 928 is not on that list.

I nearly passed a 928 with no cats at all on e85. The guy laid on the floor for 5 minutes looking for cats.

rnixon

rnixon

Thanks for the advice and reassurances. Not worrying is going to be tough though. We'll see.

GregBBRD

Check the output signal from the O2 sensor, while hooked up to the computer and hooked up to power. I have a special pigtail that connects between the O2 sensor and the loom, which makes this easier, but you can get into a plug and do the same thing.

The O2 sensor voltage, if the car is correctly working and the O2 sensor is good, will fluctuate between. .2 and .8 volts, fairly quickly...quickly enough that the signal will never "settle" at either end, for more than about a second.

That signal is the O2 sensor sending a lean signal, the brain responding to that signal, making the mixture richer, and the O2 sensor sending a rich signal, starting the process all over with the lean signal.

If the reading is slow or gets stuck at either end, you've got problems.

GTS engines generally breeze through smog inspections. you should not have any problems, unless the NOX readings are high....that's a whole different story.

GregBBRD

And use the proper spark plug. Don't let a salesman tell you that the Platin plugs will work fine.

Alan

You might want to check the vacuum line to the smog pump diverter doesn't leak and that the diverter valve seems to be working. I suspect that a lot of air pumps don't pump very well anymore and that some diverter valves don't. I know my diverter was non-op and the pump very weak when I took them off the car. Pretty sure I passed AZ emissions with it that way for several tests though...

Failing that - make sure the cats are nice and hot before you take it in. I've never tested in CA so don't know what they do - but in AZ is just a basic dyno sniffer type with minimal equipment tests - gas cap primarily. Since the Porsche cap doesn't look like anything else they have ever seen nor can connect to - they always roll their eyes and write "passed visually". Thats the extent of the checking - if you pass the sniffer they don't care what you have under the hood (or anywhere else) - pretty nice compared to CA.

Alan

The Forgotten On

I live in California an hour outside of Los Ageles. You can imagine what the smog tests are like.

I had my 81 tested and it passed very easily. I didn't have a smog pump filter on it and I have bright blue silicone vacuum lines on it, which they usually don't like.

They measure at 25 MPH and 15 MPH. Have fresh gas, nice quality plugs, a oil change, and have the cats nice and hot with a 20 minute drive.

You should pass easily with no problems, especially if yours is over 10 years newer than mine.

rnixon

I'm glad to hear stories of it being easy. Our boring car (Mazda6 ) had its first smog this year, which was a non-event, but that's only 6 years old. My GTS is 21 this year, and last had an emissions test in 2005, so I was a little concerned, but less so now. Ta!

x98boardwell

Good luck. As you know mine recently failed with high NO but after reading a ton of posts I realized that driving it down to the smog on a cold (50 degrees) morning 2 miles and not driving it before was probably the major problem.

I also heard that if it's an auto to use a lower gear which I didn't know or tell the guy. I've been stuck doing a couple other things but plan on smogging it again in a few days after changing the plugs to be safe. I did also buy a new O2 sensor as well as a relatively inexpensive attempt at a common problem.

My car runs great and it has the generic 50 state legal cats but passed last year with them on and was well below the legal limit.

Hoping after a good drive and new plugs along with my O2 sensor change that I will be good.

Best of luck.! If the car needs work in the future do you plan on doing it yourself or taking to someone?

Cheers,
Bryan

rnixon

Thanks. Good luck to you too!
I was wondering if I should do that earlier today too.
I'll do basic things - plugs, filters, brakes etc, but leave anything like the timing belt to the experts. My company has its head office in Irvine, so I'll be dropping her off with Greg for the stuff that I don't have the time / patience / equipment / skill for.

GregBBRD

For cars that are questionable or I'm uncertain about, I always ask the tech to do a "pre-test", to make sure that the car will pass. Tell him that it is the first time the car has been smogged in California and you want to make sure it is OK and everything is working properly, before actually having it tested. If he won't do that, leave and find another person to check it. If it passes the pretest, just have him run the test and be done. If it fails, get him to print out a copy of the numbers, so we (there are some really smart people on Rennlist) can figure out what is going on. Much easier than getting "hung" with the gross polluter thing and having to do this crazy process every year!

A new Porsche catalytic convertor and a good oxygen sensor could virtually make a leaking 55 gallon barrel of 20 year old gasoline, on wheels, pass. These convertors are incredibly efficient, when new....which is part of the reason they were/are so expensive. As the convertors age, getting them to pass the NOX test can be tougher. They will still clean up HC and CO, but can have a tough time with the NOX. It is not uncommon to see really super low CO and high NOX, at this point in time. A new O2 sensor will sometimes drive down the CO so low that the NOX will just go crazy.

Good luck. Yell if you need any help. Leave a message on my cell, if you get stuck, or have any questions. I'm going to be out of cell phone range and computer range, this weekend, but texts get through, eventually. 714 305 0828. Don't tell anyone this secret number!

rnixon

Thanks for all the advice.

Having read a lot on here, I've already got copper ones waiting to go in.
I did try to find (online) who'd do that, but didn't find anyone. Time to use the phone.
I'd never looked into that - certainly well worth avoiding!