hi have o2 150,5.4 ,wife came home to night backed up to unload some
wood and would not idle down stayed at 2200to 2400 rpms
code reader said p1121 cleared and now idles but a little rough
tps sencer?

thanks any ideas al

 

P1121 indicates that the readings from the MAF and the TPS are illogical relative to each other.

Check for an air tube leak between the MAF and the throttle body. Check TPS and MAF connectors for obvious faults.

Beyond that, you'll need a good scan tool (easiest) or a multimeter to check several PIDs to properly diagnose.

Steve

 

steve thanks for reply, cleaned tp and cleared code drove it for about 1 hr
last night no problems, wife drove to work in a foot of snow this morning
good so far.

thanks al