I recently purchased a beautiful garage kept, loaded, 07 Sierra SLT from an estate... Truck has
94K miles, runs & looks like new, an everything works as it should... It does have one small
glitch however that I have been unable solve... If I drive it more than 10-15 miles at one time,
the check engine lite will come on, stay on for 24-36 hrs, go out and stay out until I again
drive it for 10-15 miles again, (I usually drive no more than 3-4 miles at a time)... When I check
the failure code I get a PO121 code for the throttle position sensor every time... I get none
of the symptoms that one would expect from a bad TPS at all, in fact the truck is performing
perfectly the whole time !!! After a month or so of observation, I decided the problem was
likely heat related, so since TPS's are reasonably cheap I decided to replace it, so I bought
a new one and replaced it even though I didn't have a lot of confidence that the replacement
would solve the problem, and it DIDN'T... I'm wondering if anybody on this forum might have
any insight on an annoying, kind of non-problem, like this ?? Maybe I best learn to ignore it...
Tnx, Paul R...
94K miles, runs & looks like new, an everything works as it should... It does have one small
glitch however that I have been unable solve... If I drive it more than 10-15 miles at one time,
the check engine lite will come on, stay on for 24-36 hrs, go out and stay out until I again
drive it for 10-15 miles again, (I usually drive no more than 3-4 miles at a time)... When I check
the failure code I get a PO121 code for the throttle position sensor every time... I get none
of the symptoms that one would expect from a bad TPS at all, in fact the truck is performing
perfectly the whole time !!! After a month or so of observation, I decided the problem was
likely heat related, so since TPS's are reasonably cheap I decided to replace it, so I bought
a new one and replaced it even though I didn't have a lot of confidence that the replacement
would solve the problem, and it DIDN'T... I'm wondering if anybody on this forum might have
any insight on an annoying, kind of non-problem, like this ?? Maybe I best learn to ignore it...
Tnx, Paul R...