Emissions Question
 

Hi

I just had my 1989 300se inspected for the first time.

I replaced the air filter,oil change, and plugs.

The car just barely made it through the dyno test.

HC Limit 2.00 reading=1.43
CO Limit30.00 reading=26.77
nox Limit 3.00reading =0.75

The tech suggested the O2 sensor be replaced .He also stated these should be replaced every 30 k miles.
Does this sound right to any of you???

Hope someone out there can shed some light on this.
Thanks

Razorman

P/s Im in trouble now, no spell chack LOL

Replaced...yes. Every 30K?...not likely.

I think MB backs up the replacement for the first 100K miles, since failure is an environmental issue.

I've never heard of "recommended" replacements every 30K...unless you own an early Jaguar...in which case, you replace one at every oil change!:D

RE: Emissions
 

Thanks for the quick reply.

I ordered a new sensor from Phil.

Is this a plug and go item or,should the car be Dyno tested again
I want to do this repair my self.
I forgot to mention the car has 152,000 miles on her.
Thanks Again
Razorman

MB will only warranty an O2 sensor durning the normal warranty period, 4 year OR 50,000 miles. THIS item isn't covered by the 8 yr/ 80,000 emission warranty as this is considered a maintence item.

Is there any calibration required after changing the O2 sensor, or will the system typically find it's way back to the correct settings?

Thanks.

Back in the 1980-85 era MB did recommend O2 sensor replacement every 30K miles, but after that you only need replacement when they quit! more like every 75-90K miles. NEWER cars will turn check engine lamp on when replacement is needed.
Does sound like you do need a replacement!