I watched with interest as AlexTaylor's thread unfolded about the problems he was having getting rid of his CEL for emission purposes. An early poster called it with replacing the pre-cat O2 sensors. Nothing quite as serious as a design flaw in the Floored Fab headers like Dyno Comp surmised, or having to extend the post-cat O2 sensors (LOL!).

So, up comes my turn in December and it seems it is one thing after another.

I replaced the pre and post O2 sensor on the driver's side to get rid of those codes and I still get P2098 code. By the way, the pre-cat O2 sensor was ~$85 and the post-cat sensor was ~$99 on Amazon and took a total of about 45 minutes to swap out without need of a special tool. I was only supposed to get re-registered by the end of December, so I'm not quite sweating it...yet.

I'm frustrated as hell though. A whole litany of things keep popping up and I feel like I'm chasing my tail. At times I get a P0455 code after I floor it, and the P0505/P0507 comes up as well. Not to mention I also had the red "check gas cap" come on and the blinking gas light. But that isn't enough, now I'm getting the Brake Message on the console and of course, it is the SBC accumulator that is bad, not the whole thing (as it would be covered under warranty).

I've replaced the gas cap, but it comes up occassionally to check the gas cap. I've had to swap out my valve covers as they were leaking like the Exxon Valdez, then I did the breather cover. It is always something but one thing remains...that damn P2098!

So, anyone have any suggestions as to the P2098 code on the post-cat O2 sensor? I just replaced it and I get the error. When I had it at MB Motors, we watched the O2 sensor information and it was within the specs. Maybe it wasn't turned off when I asked when I got it tuned? Anyway, I have a question in to Jeremy at OE Tuning to see what he can do. I'm a bit worried about the P0505/0507 as there doesn't seem to be a conclusive fix for that as I've searched...other than it is a vacuum issue around the throttle body area.

Anyway, help a brother out!!

 

The red "check gas cap" and the blinking gas light is due to the faulty fuel sending units, not your gas cap. The vacuum issue is also related to the sending units as well the codes you get when flooring it. Many posts on this issue as well as a class action. Hope you get it solved without having to put your own 4 on the line.

https://mbworld.org/forums/w211-amg/...leaks-e55.html

 

Make sure you replace the O2 on the right band. P2098 is band 2?
And use the OEM sensors. I had problem using aftermarket ones on other mercs.

Gl

 

Are your wires for the rear o2 sensors extended?

 

https://mbworld.org/forums/w211-amg/...rough-sds.html

 

I am already part of the NHTSA investigation and am very familiar with that thread. I've dealt with this issue for some time, but I hadn't seen any other indications with regard to a CEL code or the blinking gas light, etc. until recently. I was simply going to see how long I could just do 3/4 tank fill ups to avoid spending some major cash to fix Mercedes screw up.

Yep, I replaced the correct sensors, both on Bank 2. I used the Bosch sensors as well.

My rear O2 sensors are extended, but from the overwhelming evidence here on the site, I don't think that is a trigger at all for this fault.

Thanks! Not sure how I missed that. Jeremy from OE Tuning suggested I clear the faults with STAR not just with an OBDII reader as they may still hang around. I'll try that and see what happens!

 

I hope you get this solved soon, good luck with it, clearing with STAR may work. My CEL, vacuum, evap, red blinking gas light and codes went away once the fuel sending unit was replaced. Cheers

 

Well crap, I was hoping to avoid doing that repair and hate to think of how many months I've gone with this issue and of course, right before inspection, it starts generating codes.

 

What he said. Fuel sending units leaking causing vapor leakage which throws the light and the blinking gas light.

 

Well, I had both fuel sending units replaced, the gas tank replaced, the gas cap replaced, the purge valve near the throttle body replaced, my thermostat replaced (the PTE thermostat I had was actually broke in half), and I've replaced all four O2 sensors. Today I had Jeremy reflash my ECU (while he was in the UAE, no less), and my second trip in my car...BAM...****ing P2098 O2 sensor code goes off.

Almost seven months and can't pass emissions...I think I'm just going to clear the code and drive up to the bay. I have no idea if the AZ folks check for the status of the sensors.

 

If you can't seem figure it out why not pull in to the emissions parking lot, clear all the codes and then have them look at the car? If it takes a little for it to pop back up then you should be good right? So glad I don't deal with all the emissions crap.

 

Yep, that is what I'm going to do. If they check for status on whether the sensors are ready, oh well. Of course I just got pulled over for expired registration after 5.5 months. I wonder if I can just change my address to a buddy's address where they don't have emissions.

 

You can make the p2098 go away via star by permanently turning off your rear O2 sensors. It is an option under development data. PM me if you want the exact coding. By disabling you will get the ready now for the rear O2 as n/a instantly and will never get a cel for p2098 or p2096.

 

Sure glad I live in a place with no emissions testing!

 

if you turn off the rear 02, it will not be "readiness state" for the emissions inspection and not pass. I would try and go by some o2 extenders (L shaped) that doesnt let the rear 02 be in the direct path of the exhaust gases. Thats what i did with mine and passed emissions. Also, my tune didnt turn off the rears.

 

I had P2096 for a long time and recently just fixed it...

have you checked for exhaust leaks near the CATS/O2s?
have you checked your wire connections from the secondary O2?

What I did was reflash the ECU back to stock with updated files though MB. That took my P2096 code and turned it into P0422/P0432 (Cat Efficiency). Upon further inspection, we dropped the exhaust to check the CATS and noticed I had an exhaust leak near the CATs that was causing the code.

I have also read that these codes can be triggered by bad CATS, but obviously check the small stuff before spending $$$$ on CATS.

+1 on Novae's suggestion. Try 02 sensor spacers. That should work as well.

How many miles on the car?

 

The readiness won't come up because its not applicable anymore if it is done through star. Just passed CA emissions that way. This is very different then what they do in the tune which is change the ranges outside of the stock limits.

I believe the OP has floored fabs, trying to get the extenders working with them will be difficult because of where the O2's are positioned.

 

I have F/F headers and I occasionally get the P2096 code after a few miles of driving. Installed some extenders but it did not help. Gonna try turning rear O2's off through STAR. Thanks for the suggestion!

 

Hey adianaty,

I tried disabling the rear O2's in STAR using some steps I came across here on the forum. I'll send you a PM to see if it is any different than what I did. Thanks!

 

I haven't checked for any leaks around the CATS/O2's, or the wire connections. Well, I did put in new O2 sensors and they looked fine to me (albeit I didn't follow them all the way to the source).

When I parked my car last night in the garage, I was at exactly 88,000 miles!

 

Those would be the next things I would check. I had the code for 2 years and did alot of troubleshooting before reflashing to the stock program (new O2s, new wires, coils, and other stuff). After getting the cat efficiency codes, we dropped the exhaust and bam there was the leak. Ive driven around for 500 miles or so with no codes.

Funny thing was the car drove great, just had a CEL. I gotta change my avatar now.

 

Sooo...how exactly do I find a leak without a lift/garage at my disposal? Well, it will be in my garage at home, but nothing fancy.

 

Ehhhh that's not something I can answer. I had my car at the shop on a lift. Its wasnt a DIY for me. Hopefully someone can chime in or help out.

 

Well, no exhaust leaks and they checked the wiring harness and they were good too. I got nothing. I'm now trying to get an inspection waiver.

I think disabling the secondary air injection in STAR may not be allowing me to get the last two readiness monitors as OK, so I can't even go in and fail the 2nd time so I can start the waiver process.

 

How many miles are on the car?

On my track rat (99 M3 with plates) I received a waiver due to the mileage and age of the car. My emissions inspector said they're granting waivers for cars over 10 years old now, especially high maintenance vehicles (e.g. BMW and Mercedes).

That, or, you can find a more 'shady' emissions place that'll turn their head and sign off on one.