Throttle body and P1121

[hcl]

Hiya! I was using a 65mm tb on my 2.5+3.0 UIM. It runs with no problem.
I installed a 75mm BBK tb a while ago, for testing purpose. It ran fine.
But a DTC code came up: P1121 Throttle Position Sensor Inconsistent With MAF Sensor High Voltage.
I've checked, there were no leaks and TP sensor was good.
TPS% is 16.8% at idle and 93.0% at WOT.
I noticed the TPS mounting screws on the BBK tb weren't vertical like stock ones. Could this be the problem?
The car is quite fine even when this DTC came up, though.
Has anyone got an idea how to solve this?

BTW, what is the TPS% of idle and WOT for stock tb+UIM?

 

[hcl]

I've discussed this with few of my friends.
They said that it could be caused by the 75mm tb. The flow became so much that PCM thinks there's an error to the MAF or TPS.
I guess I'll need a tune.

 

[striker2]

16% TPS with the throttle closed sounds too high. im not sure off hand what the percent should be but with the throttle closed the TPS voltage should be about .7 - .8V IIRC.

 

[hcl]

From Ford TSB, the idle TPS voltage should be between 0.65V to 1.25V.
Mine is about 0.9-1.0V, seems to be acceptable.
I checked my friend's 2.5 with SVT tb today. His TPS is 17.2% at idle and 92.8% WOT.