ODBII Trouble Codes reset in 1995 W140
I borrowed an ODBII scan tool for my 1995 S320 (W140). All the data I've seen shows that the S320 was one of the few models in 1995 to actually be ODBII compliant.
I pulled the following codes:
p0411 Secondary Air Injection System - Incorrect Flow
P0400 Exhaust Gas Recirculation Flow Malfunction
P0300 Random/Multiple Cylinder Misfire Detected
P0302 Cylinder 2 Misfire Detected
None of which seem to be causing drivability issues now.
The problem is that when I try to clear the codes - they don't seem to clear. That is to say, that the codes are still present immediately after the Scanner claims to have successfully cleared the codes. This occurs even if I clear the codes and re-scan a moment later with the engine not running.
Is there an issue clearing codes with the 1995 (early ODBII) S320 model, or am I doing something wrong?
I would just like to actually clear the codes and then see if they re-appear.
Any help appreciated.