1996 Mercedes-Benz C220 Q&A

1996 Mercedes-Benz C220 Question: Im trying to smog the vehiche but there are 3 tests obd2 isnt performing.

Catalyst, egr and 2nd air are the 3 test the computers not performing, on a 1996 there can only be 2. Ive tried the drive cycle a couple times but its still not passing.i need to smog vehicle. What can I do? -
Answer 1
have a mech scan it for poss pending codes and also live data to determine cause of monitors to not reset -
Comment 1
Ive had it scanned by 3 mechanics, theirs no codes, also all systems are coming up normal. Ive been told I just need to drive it. I put almost 400 miles on it , performed the drive cycle 2 times and I still have 3 tests not being performed. Question , is it normal to lock the trunk with key and have Door locks lock at the same time..locks dont lock with key at drivers door. Im wonder if theirs a short and if so, if thats whats causing 3 obd2 tests not to perform . I need to have at least one of the three test to perform in dorder to pass smog.What can I do.?. -
Answer 2
I had the same problem and was able to solve it by replacing the overload protection relay (part #0005406745) which sells on Autohausaz.com for $20 or $55 depending on which manufacturer you choose to go with. Solved my problem and I bet it would solve yours. -
Comment 1
Thanks, ill check into it. -
Comment 2
Hi any update if it fixes it. Mine is saying obd not ready? Is it same? -