1999 Honda civic LX random misfire/ running lean


New Member

i got a 1999 honda civic lx with the d16y7 engine. It will misfire under load when driving at a higher speed for awhile. if you turn the A/C on and drive it up a hill it will make it worse. i will get a P1399 sometimes but not all the time. As the throttle increases the short term fuel trim shows that its running lean.

Any help is appreciated