I have not read so much since I was in college...about OVP. my engine light comes on for some reason....code says #4...but if I go and remove the fuse in the OVP and put back in...start the engine, the light goes out...for a while anyway. I need to smog this car but afraid it will fail even tho it runs great


Any help as to why?
Warren

Code #4 is likely something wrong with your Air Flow Sensor, You may have a issue with the sensor, Sensor wiring, grounds or some other issue, How ever before you go down the long Diagnosis road, If your OVP relay has many miles/years on it, I would just replace it with a brand new, latest and greatest version of it [not a used/junk yard unit]. Clear your codes, road test and see what happens. Your OVP relay powers up your CIS and ABS control units and they are a well known Pattern Failure component. They can fail completly or just drop a circuit now and then. The vehicle will run without a functional OVP relay, but likely not well. I just fixed a CIS/ABS light issue in my 1990 190e 2.6 by replacing the OVP relay.

What is the OVP and where is it located???????