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E55 W211 AMG Not (SL)
I need help finding the source of the issue.
All started after the dreaded gas smell/leak inside the cabin after a full tank fill up.
The check engine light followed a few miles later no more than 30 miles. Maybe a coincidence.
I did not bother to check for what code was being thrown given the fact I needed to replace the fuel sending unit and was going to wait until the obvious issue was resolved to make sure the check engine light was not cause by the fuel leakage.
I drove the car about 50 miles before replacing the FSU.
Once replaced I reset the ECU. Check engine light was gone.
Drove the car 20 miles and the light came back on. I repeated the reset and after 20 more miles did it again...
Got the ECU scanned for codes. P0432 and P0422 showed up:
P0422 - Main Catalyst Efficiency Below Threshold (Bank 1)
P0432 Main Catalyst Efficiency Below Threshold (Bank 2)
The car is not moded. Has 64,000 miles.
Spark plugs have not been replaced.
RPM is steady, Idle not perceivably rough.
Here is what "logic" tells me:
I highly doubt that both sides Cats and/or both sides CO2 sensors went bad at the same time. What are the odds?!
Having said that, would a bad MAP sensor or a bad charcoal canister pressure valve, aka. Purge Valve cause this codes?
Please any suggestions are welcome. I have read many threads regarding similar issues and all i see is dealers and indis changing parts galore until MAYBE they hit the jackpot and fix it but after $$$$$ have been spent. Yes im off warranty...
Ok, where did you change out the fsu? The dealer or Indy? Dealers usually send you away after the fsu but in reality they gotta check everything including the tank and unfortunately is usually what needs to be changed as well, but try the charcoal first as I have seen that fix the issue and its inexpensive compared to the gas tank
Get a code reader with a data logger and look and front o2 sensors and rear o2 sensors and see if the rear o2 sensors are responding close to the front or if they are slow. If you end up needing converters then upgrade with headers and high flow cats or even none at all.
What year is your car? The cat's may be covered under 8yr/80k emissions warranty, if so they will be replaced with no cost to you. Only other idea, is an exhaust leak before the cats, but not likely on both sides.
As you have both banks triggering errors, very likely not a leak causing this, likely A/F problem unless you have high flow or two damaged converters. What are your mods?
Last edited by pearlpower; 09-19-2012 at 12:03 AM.
* I changed the FSU my self, pretty easy...
* Unfortunately the car is 2003. Doesn't qualified for free replacement.
* No mods, only K&Ns.
No cats sounds enticing but I think I'm ready to sell the car. Love the car but i sich cars often.
Pearlpower: I'm leaning towards A/F since the cel coincided with the FSU taking a crap.
While I hope is not cats and find it weird both get faulty at once, I;ll have them checked out.
To break tradition with lots of threads that are started and not updated with the resolution of the issue the prompted the call for help:
I refused to believe that both O2 or both Cats went bad at once so I proceeded to check for vac leaks and found nothing.
I also rubber malet the cats to hear for lose element inside, sounded solid. No rotten eggs smell...
I finally decided to check for exhaust leaks with nothing obvious showing up.
Finally, I while bad O2 throw a different CEL I was going to do a volt test of the sensors. When i went to remove the first sensor i noticed it was loose on the bung! i hoped the other bank sensor was also loose. YES! it was also very loose.
I took the sensors out and cleaned them and properly installing them back post Cat.
Reset the ECU and went for a ride and the check engine light cambe back on but knowing how O2 sensors can take longer to warm up i decided to reset ECU again and go for a 90mph highway drive with hard pulls. 50 miles later, the CEL has not been back.
Thanks all. Hope this helps the next with a similar issue.
To break tradition with lots of threads that are started and not updated with the resolution of the issue the prompted the call for help:
I refused to believe that both O2 or both Cats went bad at once so I proceeded to check for vac leaks and found nothing.
I also rubber malet the cats to hear for lose element inside, sounded solid. No rotten eggs smell...
I finally decided to check for exhaust leaks with nothing obvious showing up.
Finally, I while bad O2 throw a different CEL I was going to do a volt test of the sensors. When i went to remove the first sensor i noticed it was loose on the bung! i hoped the other bank sensor was also loose. YES! it was also very loose.
I took the sensors out and cleaned them and properly installing them back post Cat.
Reset the ECU and went for a ride and the check engine light cambe back on but knowing how O2 sensors can take longer to warm up i decided to reset ECU again and go for a 90mph highway drive with hard pulls. 50 miles later, the CEL has not been back.
Thanks all. Hope this helps the next with a similar issue.
i constantly get the 0422 and 0432 codes but i have no cats as i am running longtube headers... a/f is fine so i am assuming my o2's are junked up... just havent ordered new ones yet
Hi guys, I've hade the same symptoms wt CEL, then I've checked crank vent hose again and it was cracked y hose going to TB. Also idle run its smoother now...
09-18-2012, 08:00 PM
