Ran a quick scan on my CDI with Xentry. There are no current faults (F) but there are lots of stored fault codes (f). What is the purpose of leaving stored codes in place? Just to document the history?

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 158k miles
06 E320 CDI "Rutherford", Black on Tan, 177k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 72k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Stored fault codes can help tell the tale of what's going on. Sometimes you can get a hard fault that triggers a CEL but there can be other issues that contributed to the fault but aren't presented as a cause of the CEL. A good technician can breeze through what's stored and determine if anything else is relevant or just overly-verbose logging. This applies to most vehicles that store fault codes btw, not just Mercedes.

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Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

I was going to clear to get a "clean slate." Sounds like it would be wise to leave them?

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 158k miles
06 E320 CDI "Rutherford", Black on Tan, 177k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 72k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Why bother? The code is generated by the computer or ecu. It has software bugs like any software does. Some soft code needs to be triggered 2 or 3 times to become hard code to turn on the CEL light. Hardware may have glitches. So just leave it and don't pay any attention. I would only clear it if CEL is on, read the code first. If the same code is triggered again then you have a problem.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

I would print (or save as PDF) a baseline of what's there now, clear everything, then keep an eye on it. That way you'll know what has come back and needs to be investigated for intermittent faults.

Remember, don't put the computer on a network, either use a USB printer or a free PDF creator utility, then move the file out on a thumb drive to print elsewhere.

Getting a modern printer to work on a non-networked computer is going to be a challenge. First there's the challenge of finding XP drivers for newer printers. Also most driver installs make you go back to the internet and can't be loaded standalone.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech