paperboy72

well i am getting the dreaded po221 and po121 codes, for throttle position sensor on my 09 SS. it happened first about a month ago on my way to work. I made it to work barely, when i parked it it was running really rough, like missing badly. I have an aeroforce gauge, got the codes, cleared the codes, started up and ran fine. about 2 weeks go by and it does it again, this time right when i got on the freeway to work. pulled over and did the same thing as above, started and ran fine for about a week. i did some research here and on the web, checked my wiring and all seems to be ok.
well today on the way to work it did it twice, both times pulled over, shut down, read codes, cleared codes, waited a minute and started back up and ran fine. the first three times it did it, it was colder outside, and dry. today of course lots of snow and wetness, and did it twice today. I am leaning towards a loose wire or somehow getting moisture somewhere around a connection. what do you all think??

DrLoch

May be the TB sensor or connector getting wet.

Oldblue

Throttlebody wiring connection per

P0221 - Throttle/Petal Position Sensor/Switch 'B' Circuit Range/Performance Problem - OBDII Engine Light Trouble Code | AutoCodes.com

And the P0121 code

http://www.obd-codes.com/p0121


Loose pins in the harness connection, and or dirty TB can cause the butterfly to not close completely to the position the ECM thinks it should be

donbrew

Pzero121 etc not P OH.

paperboy72

well this got a little weird on me... let me explain
Wednesday morning it acted up again, throwing codes p0221 and p0121, got over to a Advance auto and asked to do a battery test, i was hoping they could check voltage on the throttle body. Battery tested ok except the cold crank amps were only 300 not 600 like it should be, but it tested ok still, just needed a charge. alternator tested ok, nothing was dragging on it either. so from that i know the battery is starting to go bad. leave there and head to the dealership since i was thinking they would know more about the codes and car in general. I told them the codes and left it with them. They call me 4 hrs later and tell me they cant get it to throw the codes! well i have a aeroforce scan gauge and i cleared the codes when it happens to get it to drive! I cant believe the gauge cleared the codes from the whole system, normally they are still there till you disconnect the battery right?

firemangeorge

Clearing any codes erases them from the computers memory. Doesn't matter how you do it, code reader, scanner, battery disconnect or in your case Aeroforce scan gauge.

donbrew

"clearing the codes" wipes ALL of the memory in the ecm. Including the OBDII testing data, so you can't get an emissions test immediately.

paperboy72

i went to the dealership and took it for a drive to try and get it to throw the codes, which it doesnt. funny thing is when all this started to happen, my temps were running high too, up to 210 with the heat on, i would turn the heat off and it would drop but still run hot, like 203-208. when i took it for a drive with the heat on, it was running 198-201, and not creaping up at all like it was when it was acting up. the dealership wont do anything to it without getting the codes, they suspected a carb clean, but they didnt do it. they suspect my aeroforce gauge could be throwing false codes! i am going to leave the gauge unplugged for awhile and see what happens. could the gauge really be causing me issues?

donbrew

See post#7.

I would not be surprised that those particular codes are transient.

There are several OBDII tests that must be run. Each requires specific circumstances to be triggered. Part of the code tells you which test caused it. Until all of the testing has been performed the ECM will report "not-ready" for emissions testing.

Most code readers have a warning about clearing the codes.

203F-208F is NOT over heating, a bit warm maybe. "normal" is 189F-205F, but the fan does not come on until 217F, so 215F is not over heating either.

paperboy72

Sorry Don, not meaning it was over heating, just running hotter than normal, which i know is common in the winter, but never seen it act like it has recently. maybe the thermostat is in need of changing, i am just saying it is weird that when i was having the limp mode issues, it was running hot as well, and now its not.
What upsets me when it comes to the dealer is they said the throttle body looked gummed up and needed cleaned, then they call me back and say they cant get to the throttle body for the cleaning because a "hose" was in the way and they were afraid of tearing the hose. my question was What hose? they said the cold side pipe was in the way, well how could you tell it was gummed up in the first place if you cant get to it!