Hi, I've been noticing some engine power loss in my van lately. I've change the air filter, its holder's lid where the sensor is located, I've cleaned the sensor's wet connection and the vehicle keeps failing. I have then disconnected the negative pole for a while and the problem was temporarily solved. After turning the engine on and off, the failure returned and now there is nothing I can do to take it away. Can someone give me any idea or solution? Thanks!

I’ve been working on this truck for a while now and I’ve managed to fix all problems that my check engine light reports. There is no longer any check engine lights but I’m still experiencing some problems. When ever I’m in a parking lot about to reverse park, my truck will suddenly cut its self off. I am also experiencing some poor engine responses as well as delayed acceleration. I’ve replaced spark plugs/wires, all O2sensors, EGR value, air filter, and gas filter also have done a gas treatment.

The light comes on at 75 mpd, code P0300, changed wires, air filter, added fuel injector cleaner(twice), runs fine, no change in performance. What else should I do? or not worry about it?