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Old 02-06-2010, 04:23 PM
Texholdem Texholdem is offline
Texholdem
 
Join Date: Mar 2007
Location: Dallas
Posts: 756
HELP! 1990 300CE failed Texas emission test

Results for high speed/low speed:

HC (PPM) 454/445 (Standard = 140/144)

NOx (ppm) 3512/3189 (Standard 984/1077)

According to the info sheet possible reasons are:

- O2 sensor
- EGR valve or hose
- Ignition timing and system (advanced timing and ignition components are some of the most common problems)
- Pirimary feedback sensor failure including MAP/MAF, TPS, RPM and CTS sensors.
- Vacuum lines (deterioration of vacuum lines, inlet manifold seats, and become more prevalent causes with age).
- Catalytic converter. (edit: replaced Jan 09, so it can be excluded)

My car has no OBDII how can I narrow down the cause? Is there a pre-OBD device with push buttons somewhere? and why there is no CEL at such bad numbers?

Before the inspection I had fuel system cleaned, I changed spark plugs and coolant.

I've got 14 days to get re-inspected; I'd appreciate your inputs since the spectrum of causes is to wide for me.
__________________
1996 E320 since 1/16/08, 171K miles as of Feb 2011

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1989 300CE - R.I.P. Dec 29 2007
Other MBs (sold): 1992 300E-24 - 1979 350SLC - 1984 230E - 1990 300CE

Last edited by Texholdem; 02-06-2010 at 09:26 PM.
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