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1990 200E, 1997 W210 E200 Wagon
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56 Posts
Discussion Starter · #1 ·
Hi to all.

My 1997 E200 estate failed its test (National Car Test, every 2 years in Ireland) today on its CO (carbon monoxide) levels. The limit is a maximum of 0.30 vol% at high idle and my car tested 0.44vol% at 2,670 rpm so it failed. It passed at low idle (760 rpm at 0.32 vol%) though.

I have 28 days to fix this. I would very much appreciate any advice I could get on how to remedy this. For reference HC passed at 43 ppm (high idle) and lambda read 1.0, a pass.

Many thanks in advance for any advice.

Adrian :confused:
 

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99 E430, 01 E430 Sport, 00 SL500
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3,261 Posts
The possible fixes get more expensive down the list.
Run the engine hot before smog test, higher octane gas, air filter, fuel filter, spark plugs, wires, O2 sensors, MAF sensor, catalytic converter, ...
If permitted, re-test at smog station next to the beach for cleaner air intake, avoid downtown smog station at all cost.
 

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1922 Ford T no OBD, no ECU, no SCN
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37,842 Posts
You are pretty close. I assume no codes since the test would fail just on that.
What is the mileage on spark plugs? Is your engine equipped with MAF?
 

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Registered
1990 200E, 1997 W210 E200 Wagon
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56 Posts
Discussion Starter · #4 ·
I guess the mileage on the plugs would be 20k+. Not sure if my car has MAF. How would I find out?
 

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1922 Ford T no OBD, no ECU, no SCN
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37,842 Posts
We have only few members here from Europe, while most are in US, where this engine was never sold.
This way you can count on general advise, but for specific info you might be better going into UK forum.
If you are not sure if you have MAF, than going to mechanic who could do some testing would be advised. 20k on plugs is not much, but than what plugs are they?
 

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'01-E320 & 02-ST2
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31,631 Posts
The first thing I would do is check for codes. You may have something pending that may help point you in the right direction.

That said, both of those numbers are a bit high. You could be running a little rich, which could be a bad O2 sensor or a dirty air filter. Or you could have a mild misfire, perhaps caused by a vacuum leak. Start easy: get codes checked and pull the intake plumbing clear back to the manifold, check all vacuum lines and breather hoses. May as well clean the throttle/butterfly valve while the intake is off and be sure you align the gaskets as you reassemble. Pull the plugs and inspect them, if they are the multi-tip variety chuck them for regular plugs. If any are particularly sooty, you may have a bad injector on that cylinder.

Just some basics to check out. Good luck
 

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Registered
1990 200E, 1997 W210 E200 Wagon
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56 Posts
Discussion Starter · #7 ·
thanks for all the advice. I'll drop the car in for a service next week and get the basics done and let you know how i get on.
 
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