markayash

I have a 2002 clk430 and have been getting the p2098 code for a few months..I have cleaned the MAS and replaced the fuel filter ( which made a big difference on how it runs ) but code keeps coming back..I did some research and did look at the short term reading on my scanner and bank 2 long term is -5.5 compared to bank 1 of 8 but short term on bank 2 is higher most of the time..When Bank 1 is -7 bank 2 might be 5 o r 6..Constantly changes but bank 2 short term is always 6 to 8 points above bank 1
Looking for more ideas, I was a mechanic years ago when we changes Jets and willing to fix it myself but not sure what to try..

Serndipity

https://www.obd-codes.com/p2098

markayash

I have read similar articles but hoping other that had the same issues might list what fixed theirs..I am hoping it will clear up..Strange part is after replacing the fuel filter it is runs a LOT better..More power, smoother idle and better gas mileage..I did put a can of techron in it to see if maybe with better fuel pressure and a cleaner it will fix the issue.
I don't think the car could run any better, just keeps saying p2098..Does the scan tool really clear the computer or do you think I need to remove battery terminal completely?

Serndipity

Most scanners should be able to clear 'emission, related codes. Disconnecting the vehicle battery will erase some stored controller settings, but not diagnostic trouble codes, because their stored in non-volatile memory, until cleared.

Can't recall ever seeing any threads in the W208 forum relating to the P2098 code and suggested the above link, which discussed the code in detail (e.g. symptoms, potential causes, diagnostic and repair procedures etc.).

Our W208 share a similar power-train as many other Mercedes models, so my suggestion would be to search the entire forum for P2098 related issues. If you use the forum search tool, use https://mbworld.org/forums/ and only P2098 as the search (otherwise you'll get numerous hits with any of the search terms). Also do the same at http://www.benzworld.org/forums/ .

Since you're not getting any engine specific codes, you might want to focus on an engine vacuum line leak and/or an issue within the exhaust system.

markayash

what i noticed is its random But if i drive it hard for just a minute the check engine light comes on??

GatorMB

Hunch: bad vacuum leak or fuel injector. Start with plugs n wires.

markayash

I guess that' is one of my question...Could a bad/old plug cause a lean mixture on s2b2? It has a 135K anbd might have the orig plugs..Owner wasn't clear on that.

Thanks

GatorMB

Worn plugs cause all kinds of problems. Once the air box is removed and the right person identifies issues like PCV pipes broken or rotten vacuum pipes, the engine revives.
Plugs and wires to start mate.

markayash

Also having trouble getting the emissions machine to read my computer. I came home tonight and when I measure voltage at the fuse it was 11.5 with the car shut off measure voltage at the battery it was 12.5 trace it down to a loose battery terminal wire on the ground side.
going to have the car tested again tomorrow hopefully they can read it before it said no DLC voltage

markayash

I hope it fixes the issue, the code came up after a few wide open blast or long idling so makes sense..i hope

markayash

Failed emissions at a BP station and while I was upfront paying they were in the back pulling out fuses. Got them to leave it alone took it to a European shop around the corner so hopefully they can figure out what's going on.. when I got in the car. ABS alarm is flashing it went off so hopefully everything is okay don't know what they did to the car before I get back there