Another P0300
 

Greetings All

I have a 2002 Protege LS 2 liter which started to idle rough then MIL came on. Plugs are almost new and look good, wires and coils seem OK. I cleared the code and tried to see if the problem would return. No MIL, but sensor data shows very low O2 output from #1 sensor approx .03V. #2 is .4V Fuel system says system fault in open loop, even after running for 1/2 hour and at normal temp. MAF reports .4 lb./min @ 703 RPM idle, can't find any vacuum leaks. Does anybody have any ideas where to go next?

Thanks for any suggestions

Paul

RE: Another P0300
 

try the injectors i have a 2000 1.8l dohc and the spark plugs were burned out and the injectors were pluged up, the only way i know how to check the injectors is the run off test there is a certain amount of fuel that doesn't go into the cylinders and with this test you disconnect the hoses on the injectors leading back to the fuel tank hook up hoses and have them going into bottles make sure there all the same size and the injectors should fill each bottle at the same pace if one fills faster than the other then the injectors might be the problem, or you can put a bottle of fuel injector cleaner into you tank and see if that stops the rough idle lol.