1999 Ford F150 5.4L Triton with engine code P1127 and running rough

Question

My 1999 Ford F150 5.4L Triton is running rough in the morning, with poor gas mileage. checked with scranner and got the P1127 code .no check engine lite is on and no stored codes

Answer 1

HI there

This code only means the exhaust isn't warm enough for the down stream O2 sensor to be tested. in most cases the sensor is the issue.

Answer 2

P1127 Ford Code - Exhaust Not Warm Enough Downstream O2 Sensor Not Tested
Read more: https://www.autocodes.com/p1127_ford.html