i got a d16y5 and i got a P1162 CEL. its is Primary Ho2s (No.1) Circuit Malfunction. Ive noticed my gas milaege go down also. What is the cause of this.

 

Bad primary O2 sensor, bad wires, or bad ECU. You need to do some electrical detective work to pinpoint.

 

It sounds like your oxygen sensor is bad and causing your bad gas mileage.

 

where should i start pin pointing. and its the o2 sensor on the header right?

 

Clear all codes from the ECU (remove 7.5A Back UP fuse under hood for a few minutes and then reinstall), start engine and let it idle, and watch the time on your watch to determine how long it takes for the CEL to turn on. If the CEL turns on before 2 minutes have elapsed, then pull the code to verify it is P1162. If the CEL does not turn on by 2 minutes or longer, then do this to see whether you now get CEL P1162:



Post the the results of these tests.

 

Ok i cleared the code and took out the fuse for about five minutes. i put the fuse back in and started the car and let it idle for 2min. the code didnot come on. so i took the car out and drove it for about 4-5 miles in 3rd gear at 1500 rpm. the code still has not come on yet. i even drove the car real hard. going through all the gears popping vtec. The code still has not come back on yet. The car was on for a total of 28 minutes. Ill just keep checkin to see when it comes back on. WHAT WOULD BE THE PROBLEM IF IT CAME ON UNDER 2 MIN? AND IF IT CAME ON WHILE DOING THE DRIVING TEST?

 

At this point, do absolutely nothing unless/until the code returns.