So my CEL continues to come on and I am continuously getting 11 flashes which everyone has told me is the air injection system. So now how or where do I correct the problem, can someone please point me in the right direction? What part or part number should I look at replacing? I have already replaced the air diverter(?) and the check air valve, both located on the passenger side by the smog/air pump. I feel like I have been chasing my tail with this issue and I am completely lost. Thanks guys!
1990 190E 2.6

__________________

1990 190E 3.0L

Just like most air injection systems, the O2 sensor is the monitor that see if the system is working.

When the engine is warmed up & the O2 sensor is in closed loop (controlling fuel mixture),
The engine computer will engage the air pump. At the same time open the diverter valve and then watch the O2 sensor for very low voltage output.

Something in that air injection CHAIN must be missing.
Does the pump ever run?
Is the O2 sensor "fresh"?
Are the vacuum lines from the switch-over valve to the diverter valve in good condition?

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

thank you mb doc, it makes sense to me now. diverter is brand new, O2 sensor is less than a year I think, smog pump is maybe 2 or 3 years old. here is my list off repairs and routine jobs: **Mercedes-Benz**
*Belt replaced 10/23/10
*Air pump diverter valve replaced 10/23/10
*Oil Pennzoil 20-50 changed @ 265,730 9/16/10
*Oil filer Bosch replaced @ 265730 on 9/16/10
*Water pump replaced 7/24/10
*Thermostat replaced 7/24/10
*Belt tensioner replaced 7/24/10
*Belt shock replaced 7/24/10
*Coolant replaced Zerex G-05 7/24/10
*Radiator flushed 7/24/10
* Oil cap gasket replaced 7/24/10
*Belt replaced 7/24/10
*Coolant tank sensor replaced 7/24/10
*Coolant bypass hose replaced 7/24/10
*Radiator expansion tank replaced 7/23/10
*Radiator cap replaced 7/23/10
*Overload Protection Relay replaced 7/9/10
*Transmission fluid changed 7/3/10
*A/c evacuated and recharged with R134a 6/10/10
*A/c cut off switch replaced 6/9/10
*A/c temperature sensor replaced 6/9/10
*Auxillary fan switch replaced 6/9/10
*Air temperature sensor replaced 6/9/10
*Transmission pan gasket replaced 6/7/10
*Air filter changed on 5/22/10
*Transmission filter changed on 5/22/10
*Transmission fluid changed on 5/22/10
*Distributor cap changed on 5/22/10
*Distributor rotor changed on 5/22/10
*Fuel filter changed on 5/22/10
*Oil filter- Bosch Premium part number (3421). Done on 3/13/10 @ 254747 *Oil
GTX 20-50W 5.5 qts done on 3/13/10 @ 254747.

*Oil filter- Bosch Premium part number (3421). Done on 11/9/09
*Oil Mobil 1Fully synthetic 15w-50 6 qts. Done on 11/9/09 @ 248,946 miles.
*Radiator flushed. 1 gal Zerex G-05 added. Done on 11/09/09 @ 248,946 miles.

*A/C-heater control valve done on 11/5/09

*Check air valve. Done on 10/9/09

*Bosch O2 sensor replaced. Done on 10/7/09 @ 246,939

*Bosch H9DCO Spark plugs 6 total. Done on 10/6/09 *Bosch spark plug wire
set. Done on 10/6/09 @ 246,560

*Oil filter-Mobil 1 high mileage. Done on 9/20/09 *Mobil 1 Fully synthetic
extended fuel economy 0w-30 6 qts. Done on
9/20/09 @ 245,763 miles.

*Oil filter-Mobil 1 high mileage
*Air Filter- Purator air filter
*Mobil 1 Fully synthetic extended fuel economy 0w-30 6 qts. Done on
5/26/09 @ 240,000 miles.

maybe I'll recheck the O2 sensor. I'm sure the smog pump cycles on when I turn on the car or whenever its supposed to.

__________________

1990 190E 3.0L