Failed Hydro Carbons big(?) and CO please help gurus.


Mode-----------CO%---------------HCppm-----------------RPM-------Dilution
2speed idle---Limit-Reading-P/F-----Limit-Reading-P/F---Read-Resu-Read-Resu
Idle----------1.2---8.74----Fail-----220--577----Fail----703-Valid--18.1-Valid
2500 rmp----1.2---8.34-----Fail-----220--336----Fail-----2548-Valid--18.0-Valid


I am thinking O2 sensor.
Any Ideas where I should start?

Edit: this would be on my 86' M103 300E -as per my sig. BTW

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html