I wonder if you are attributing more precision to your measurements than is warranted. I could see that your car is performing very close to spec, but that your measurement is a bit off.

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"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

I've seen a procedure for gassers where the temperature differential across the cat is measured. If the difference is minimal, it indicates a bad cat. I'd imagine this does not work on diesels, though.

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RenaissanceMan Labs: where the future is being made today.

Garage:

2017 Chevy Colorado Diesel (nanny state emissions)
2005 Volvo S40 T5 AWD, 77k
1987 Mercedes-Benz 300D turbodiesel, 4 sp auto, 156k - 28.7 mpg
1996 Tracker 4x4, 2 door, 16v, 3 sp auto. 113k - 28.6 mpg

WARNING: this post may contain dangerous free thinking.

I don't exactly, but as I recall there's a port somewhere on the exhaust manifold where a gauge can be attached. It could very well be the EGR port. You'd have to check the FSM, which I don't have installed on this PC.

I got a nice little boost in power plus lower coolant temps when I removed my cat, it's basically a ceramic (maybe?) piece filled with very small longitudinal "straws". If you want to keep it, you could try blowing some of the soot out with an air compressor.

Found it!

Attached Files

14-0150.pdf (206.7 KB, 115 views)

Thanks, Mxfrank! I'll check that after cleaning the carbon out of the intake.

__________________
RenaissanceMan Labs: where the future is being made today.

Garage:

2017 Chevy Colorado Diesel (nanny state emissions)
2005 Volvo S40 T5 AWD, 77k
1987 Mercedes-Benz 300D turbodiesel, 4 sp auto, 156k - 28.7 mpg
1996 Tracker 4x4, 2 door, 16v, 3 sp auto. 113k - 28.6 mpg

WARNING: this post may contain dangerous free thinking.

Cool! Note on page 3 the list of 7(!) things to check before renewing (or in this case removing / modifying) the trap oxidizer, IF the back pressure is too high.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Why bother, just ditch the trap ox.

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CENSORED due to not family friendly words

Well, for one thing, if a clogged trap oxidizer is not the problem, then you will have done a lot of work for nothing and are now polluting the air more than you need to.

Here's the list:

1. EDS brief test (07.1-1120)
2. Full throttle stop on injection pump (30-1010)
3. Air cleaner element
4. Charge pressure (09-5911)
5. Delivery of fuel pump (07.1-5701)
6. Fuel filter and pre-filter (07.1-5563)
7. Start of delivery (07.1-8240 or 8244)

Hmmm, air and fuel filters, throttle linkage adjustment, injection pump timing, many simple things to check that are routine maintenance or not hard to check with the proper tools.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

And also notice that the regeneration procedure is simple...load up the engine by running at 4000 RPM for two minutes. You can do that by shifting into third and driving hard. The oft-mentioned italian tune-up, documented.