Emissions testing

[MikeD]

As my time boils down to 20 days left to pass my Illinois emissions test, I was wondering if any of you know why a 1996 C280 may have system monitors that are not ready.

I tested my car twice. Both times my car got rejected because of system monitors that are not ready. Between tests, I put on 1500 miles and that only got rid of 4 of the 6 monitors that were not ready. So 1500 miles later, I am left with:

EGR Flow: not ready
Secondary Air System: not ready

Any ideas on what could be wrong?

[W202FTW]

They still make your 96' test for emissions? LOL

Regarding the EGR Flow, pull out the EGR valve ( right on top of the exhaust manifold ) and flush the thing with a can of carb spray. Replace the gasket when you're done.

For the secondary air injection system, drive the car till it reaches about 80*C, then let it run at idle for about two minutes. This should complete the check cycle. If not then there's probably going to be an issue with the Y32 relay or the air pump. If you're still not sure, you can always take it to the dealership or a good indie tech and have them run an emissions check through STAR to see if it's ready.

Do you have to pass all 6 monitors? Or can you get away with 5?

[MikeD]

It's looking like '96 is the cutoff year. As far as monitors go, the only that seems to not matter if it is "not ready" is the evap monitor.

I just bought a can of carb spray, trying the cleaning tomorrow!

[W202FTW]

It's looking like '96 is the cutoff year. As far as monitors go, the only that seems to not matter if it is "not ready" is the evap monitor.

I just bought a can of carb spray, trying the cleaning tomorrow!

Lemme know how that works out and if the one or both of the monitors clears itself. I happen to be a licensed state inspector for Massachusetts and see this stuff all the time at the Honda dealership where I work.

[MikeD]

Unfortunately, I'm still getting the same codes, but damn that carb spray works well! It took all the gunk out of the egr valve.

[W202FTW]

I pulled mine out ( probably the first time in it's life ) at 196k and it took several cans of carb spray to fully clean it out.

You might have to take it to an indie or the dealership to check out those monitors. I typically get MOST of the emission failing ( usually cat and EVAP monitors ) Hondas to pass by forcing the ECM to run a test while the car is turned off. I don't how Mercedes STAR works ( don't have one ), but maybe they can do something similar.