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2001 c350hd p1220 p1221

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Hello everyone, new to this forum and in need of some help and guidance… I have a 2001 c3500hd with p1220 & p1221 and with the dreaded REP on the dash!

replaced the throttle body due to a p1516 but no longer have that code. I’ve changed the tps sensor and app sensor. 
Although I changed the tps, I checked the voltage on tps1 & tps2… 

I noticed that I got diff readings on tps1

at WOT… Idle….and closed..

but when I checked tps2, I just got one reading through the movement of the butterfly….

what should the tps be reading???


Any help would be appreciated 🙏🏽

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