No the muffler isn't original. The original owner replaced both the muffler and the resonator and I changed the muffler about 12 years ago. The cat has never been changed. I plan to change the cat with a Walker.

Hi Everyone

Just wanted to pass along an update.

I changed the CAT and the vehicle passed smog today. NO way down, HC is down as well but still a bit high.

Still pan to change the O2 senor, it is super tight, multiple applications of PB blaster, will try to remove in teh next day or two if still tight will have someone take a torch to it.

Thanks to everyone for their input and suggestions.

See attachment for smog test results

A new cat works wonders, and should cover up minor engine issues for awhile.

Did you try heating up the bung for the O2 sensor with a propane torch? It'll kill the sensor, but it's probably close to death already. The heat differential between the bung and the sensor should help fracture the thin layer corrosion in the threads. Once it starts moving, twist the sensor back and forth to grind the chunks of corrosion into dust, so the threads don't get jammed or tear (galling). Install new sensor with careful application of anti-seize on the threads to make removal easier next time.

No didn't apply heat yet, just some PB Blaster. If it doesn't come out next attempt, heat will be applied.

Are California Smog test requirements the same across the state and are they the same for all vehicles that are required to pass a smog test?

I just had my 1996 Mercedes C280 smog'd and my print out showed that my car could not go have a HC reading of higher than 51 at 15 MPH and not higher than 35 at 25 MPH.

However, murphysf's California Smog snippet showed that his car's max HC could have been 110 at 15 MPH and 77 at 35 MPH.

Stevester, you don't say where you are from. As far as I know the smog requirements are State wide and the certificate doesn't refer to MPH but to RPM's. I just pulled my last test on my '97 CL600 with the following results:
Idle HC (max) 100 (Ave) 17 (Measured) 10
2500 RPM (max) 130 (Ave) 12 (Measured) 11
I don't know where you got your numbers or who Murphy is. My hulking 12 cylinder beast passed with flying colors but I do have new O2 sensors and Magnaflow cats that were installed a year ago. But then the car only has less than 70K. However, this is my 5th Benz and I have never had any smog pass problems with any of them, even those over 200K miles.
Anziani

It sounds like you had an acceleration simulation mode (ASM) test, but apparently there are still some areas in CA that just do the old two speed, no load test at idle and 2500 as reported in the previous post.

The ASM test is run at 15 and 25 MPH with more load than is required to maintain those speeds on a level road, and that's why it simulates acceleration.

The cutpoints are based on the year group of the car and the weight, in 50 pound increments, which is computed at curb weight plus about 150 to 200 pounds to account for at least a driver, and the newer the year group, the lower the cutpoints.

The Bureau of Automotive Repair has a single page pdf on their Web site with a formula for computing the cut points, and the variables to plug into the formula for any year group are in a table. This is because certification limits became lower over time. Run the numbers for your car in the proper year group and you should come up with the same cutpoints as on your emission test report.

The ASM test reads proportional emissions in percent and ppm, but the original certification test requirements were based on absolute emissions in grams per mile. Thus for the same engine a heavier car will have lower cutpoints than a lighter car, an example being that the 260E/300E 2.6 will have slightly lower cutpoints than a 190E 2.6 within the same year group.

I have had numerous discussions if not outright arguments with the BAR that there is no way to directly correlate proportional emissions to the absolute certification standards. They have grudgingly agreed, but claim that the cutpoints are based on statistical analysis of their emission test database, and apparently the EPA is okay with that, but it becomes a real issue if you bust a cutpoint by a few ppm.

Duke

I received a letter from the NJ Motor Vehicle commission telling me my 1988 300CE no longer had to be inspected. They instructed me to remove the inspection sticker (which is still there) from the front windshield and carry a copy of the letter in the glove box, which I have done.
Fwiw, I have 153,000 on the Odometer, 112,000 are mine since 2001.;)

See attatched
 

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