Failed SMOG high HC and NO on low speed - PeachParts Mercedes-Benz Forum

david s poole · #1 05-19-2011, 12:05 PM

based on your numbers i strongly suggest that you get a cat replacement.here in texas that can be done for less than 300 installed and will make a huge diff to your readings and you won't have to sweat the little stuff which may or maynot help.the reading of 15.2% co2 means that the engine is running very well.[it's a measure of efficiency] and is one of the reasons i'm saying replace the cat.the other is the high nox.just did this on a client's car 3 days ago and then passed with flying colours.

2wheelsoff · #2 05-19-2011, 01:39 PM

Quote:

Originally Posted by david s poole

based on your numbers i strongly suggest that you get a cat replacement.here in texas that can be done for less than 300 installed and will make a huge diff to your readings and you won't have to sweat the little stuff which may or maynot help.the reading of 15.2% co2 means that the engine is running very well.[it's a measure of efficiency] and is one of the reasons i'm saying replace the cat.the other is the high nox.just did this on a client's car 3 days ago and then passed with flying colours.

thanks for the suggestion. I have access to a mig so can do the cat for little $$$ so just some labor and about $120ish on amazon of all places. retesting is not very expensive if I return to the same shop, so will try o2 first and if that doesn't cover it take care of the cat.