94 Tempo - 4 Cylinder Check Engine Light - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

DaughtersTempo · 01-15-2004, 16:50

I have a 94 Tempo - 4 cylinder, 5 speed, 165,000 miles. The Check Engine light started coming on about 30,000 miles ago. It was very infrequent and only when above about 65 mph. I paid the Ford dealer to read the code and he said it was the O2 sensor. I had changed the O2 sensor once after the light started coming on and it made no difference. But I changed it again. Again, no improvement. Since the problem started, the light is coming on more often and at lower speeds. Now it routinely comes on at 45 mph.

Any ideas? Thanks a lot. Phil

DaughtersTempo · 03-03-2004, 17:45

As a followup, the problem has been solved. I am embarrassed to say the problem was a vacuum leak. That should have been an obvious thing for me to check. The O2 sensor was not bad; it was properly detecting that the engine was not running right because of the vacuum leak.

LunaticSVT · 03-07-2004, 15:21

Good to hear that it was only a vacuum leak.