How hard is it for a '91 to 'pass smog' in CA
 

I am looking at a '91 Mazda in CA and the seller tells me it runs well and 'passed smog'.

Is this reasonably difficult to do? Enough so that I can assume nothing major is up?

Thanks

if there is nothing wrong with the car...and it is all intact, it isnt hard.

only pain is that at that age, the car is going to a "test only" station.

If it passed within 90 days, you can buy it and not test until 2 years. Older than '96 is OBD1 and that's another plus.

Thanks, I'm not worried about having it tested again. More wondering if the fact that it passed means it's fairly sound.

If the test was actually done, and actually passed, it is pretty sound.

Compliance is the trick. If you look like you have money, it will not pass without some 'repairs'.

Flame me if you want, but that is how it works.

The slot machines in Vegas have about the same payout percentage as the smog machine.

Is it a rotary?

I understand some of them can be difficult.

The emissions test only looks at emissions. Some engine problems will make it fail. Burning oil would. Running rich would. Missing or bad ignition wold. Also, the rest of the emissions system will have to be ok too. Visual test of the vacuum lines, EGR, PCV, gas cap etc. The cat will have to work along with the O2 sensor.

That said, there are a lot of things that can be wrong with an engine that would not show in an emissions test. Bearings, even valve stems, some head gasket leaks all that would not have to show in the exhaust.

The smog check does not do a safety inspection whatsoever. The car can be a complete wreck and still pass smog.

In summary, passing smog is a good thing. Have him send you the certificate. It is however not a guarantee that the engine is good, leave alone the rest of the car.

Hope this helps.

George

All things considered, it's certainly not a bad thing. I agree w/ George that theoretically it could be a bad motor and pass but I've never seen it happen. The vehicle has to be running pretty close to perfect to pass in CA. They also test under different rpms and under load, using a "rolling road" that is like a dyno. I consider a passed smog test to be an excellent indicator on a used car or truck.

The dyno days are gone, not required anymore. Additional things now are a pressurization of fuel tank thru the cap and a leakdown rate requirement for 'escaping vapors', as well as the vacuum requirement for the cap itself. Ignition timing, air filter check, and in 2010, a check of air pressure in tires, as well as a check of nitrogen content in tire air as well.

Really? Since when?

Now that was a stupid silly post. Of course we have dyno tests here and we have gas cap tests. Then there's the visual part, but when I took the Boxster in, they didn't bother looking in the engine compartment. Too much trouble. So, I guess there are ways.....

Well, it may have been silly, actually my point is that the whole 'smog check' thing is silly.

However, it's true. I stood 5 feet away from a chatty tech as he did my '91 Toyota truck. No dyno. The 2500 RPM check was done in neutral. He explained what he was doing, and talked about all the changes that were coming. This was a 'Gold Seal' facility, meaning it was not a 'test only' place, they were authorized to do smog repairs as well. They did a pressure test of the entire fuel system by pumping air into the fuel tank thru the filler neck, and the machine checked the leakdown rate. The cap was vacuum tested as well.

He said the rules all change again in 2010, and he said that it was going to be even 'sillier' as Milt would put it.

Ok, this is all great information. The car in question was donated to a charity auction and was being sold today. I had pictures, a very clean 'carfax', and the fact that it had passed smog. Not much beyond that. I'm waiting to hear back from the seller now.

No, Miata

They put my Targa on a rolling road when they smogged about six months ago.