Throttle body help - P0121 code
Thread Starter
Racer
Joined: Oct 2008
Posts: 415
Likes: 5
From: Owensboro Ky
St. Jude Donor '11
Throttle body help - P0121 code
I've been showing the code P0121 for a pretty long time. The guys at the chevy truck forum say to clean the throttle body and reset the computer. So two days ago I cleaned the throttle body and ever since then my car is driving terrible. The car is an auto and the paddle shifters will make it stall out and the car doesn't want to quit going. It'll go 35mph without me touching the gas. It'll look for gears slowing down and the shifts are pretty strong. Highway speeds are fine, but the stopping is a problem. It'll take a minute to idle back down to 600 rpm.
Long story short, does anybody know how to reset the computer? I thought you just had to drive it and it would recalibrate itself. I've put 150 miles on it and it still drives like crap.
Long story short, does anybody know how to reset the computer? I thought you just had to drive it and it would recalibrate itself. I've put 150 miles on it and it still drives like crap.
Melting Slicks
Joined: Dec 2011
Posts: 2,209
Likes: 16
From: Yorktown Heights NY
Try disconnecting the battery for a few minutes to reset the ECM... If you messed up the MAF while you cleaned the throttle body you could be scre__ed... The wires are delicate and it has to be re-mounted in the same orientation and rotation as it was before.
P0121 is a "Throttle Position (TP) Sensor 1 Performance ECM" code. There may be a dirty throttle position sensor.... take it to a reputable vette shop?? Did you do an (advanced) search on the forum for this code?? Probably not the first one with this problem... just saying.
Let us know what it turns out to be!
P0121 is a "Throttle Position (TP) Sensor 1 Performance ECM" code. There may be a dirty throttle position sensor.... take it to a reputable vette shop?? Did you do an (advanced) search on the forum for this code?? Probably not the first one with this problem... just saying.
Let us know what it turns out to be!
Thread Starter
Racer
Joined: Oct 2008
Posts: 415
Likes: 5
From: Owensboro Ky
St. Jude Donor '11
Try disconnecting the battery for a few minutes to reset the ECM... If you messed up the MAF while you cleaned the throttle body you could be scre__ed... The wires are delicate and it has to be re-mounted in the same orientation and rotation as it was before.
P0121 is a "Throttle Position (TP) Sensor 1 Performance ECM" code. There may be a dirty throttle position sensor.... take it to a reputable vette shop?? Did you do an (advanced) search on the forum for this code?? Probably not the first one with this problem... just saying.
Let us know what it turns out to be!
P0121 is a "Throttle Position (TP) Sensor 1 Performance ECM" code. There may be a dirty throttle position sensor.... take it to a reputable vette shop?? Did you do an (advanced) search on the forum for this code?? Probably not the first one with this problem... just saying.
Let us know what it turns out to be!
Hey I really appreciate the info. I was pretty careful when taking everything off. When you say the the MAF has to be in the same orientation and rotation, are you talking about it has to be in the same spot everytime? I have a vararam intake and just put it back as close as it was before.
The biggest downfall is, there's not any vette shops around. I searched for the code on here, but couldn't find much. When I googled the code, it came back with tons of chevy trucks with the same problems I'm having.
Will disconnecting the battery cause me to lose my dyno tune?
Thanks again!!
Melting Slicks
Joined: Dec 2011
Posts: 2,209
Likes: 16
From: Yorktown Heights NY
You will not lose your tune when you disconnect the battery.. It resets the air/fuel trims but they get recalibrated automatically by driving the car. That's what the others on the truck forum were suggesting. I'm pretty sure you have a bad or dirty sensor somewhere.. Chevy dealer??
I'm sure I've read about the TP sensor codes on this forum before..
Check this thread..
Another explanation of P0120
check it out.
I'm sure I've read about the TP sensor codes on this forum before..
Check this thread..
Another explanation of P0120
check it out.
Melting Slicks
Joined: Dec 2011
Posts: 2,209
Likes: 16
From: Yorktown Heights NY
Here one more thread worth reading... Might just be connection somewhere involving the Throttle body or the Sensor... Don't know how comfortable are poking around in there, but you did take it off to clean it... I would be taking off all the connectors at the MAF and TB and cleaning/checking them out.
(advanced search can be your friend)..
(advanced search can be your friend)..
Thread Starter
Racer
Joined: Oct 2008
Posts: 415
Likes: 5
From: Owensboro Ky
St. Jude Donor '11
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Thread Starter
Racer
Joined: Oct 2008
Posts: 415
Likes: 5
From: Owensboro Ky
St. Jude Donor '11
You will not lose your tune when you disconnect the battery.. It resets the air/fuel trims but they get recalibrated automatically by driving the car. That's what the others on the truck forum were suggesting. I'm pretty sure you have a bad or dirty sensor somewhere.. Chevy dealer??
I'm sure I've read about the TP sensor codes on this forum before..
Check this thread..
Another explanation of P0120
check it out.
I'm sure I've read about the TP sensor codes on this forum before..
Check this thread..
Another explanation of P0120
check it out.
Man I really appreciate all your help. I never knew (or looked hard enough) for the advanced search. I always used the bar at the top that pulls down. The chevy dealer here sucks. There's very few vettes around here and they probably don't get driven enough to have problems. I'll probably take it in anyways and see what they say. I don't really want to mess with any of the electrical stuff.
I appreciate it!!
Thanks everybody!!
Burning Brakes
Joined: Apr 2011
Posts: 967
Likes: 0
Thread Starter
Racer
Joined: Oct 2008
Posts: 415
Likes: 5
From: Owensboro Ky
St. Jude Donor '11
Update.
I disconnected the battery this morning for about 30 min or so. Then drove about 10 miles to test it. The drive was complete crap. An hour later I get back in the car and it's almost perfect. Thanks everybody!! I'm going to drive it a few more days to see if it gets better. I think disconnecting the battery worked.
Thanks again everybody!!
I disconnected the battery this morning for about 30 min or so. Then drove about 10 miles to test it. The drive was complete crap. An hour later I get back in the car and it's almost perfect. Thanks everybody!! I'm going to drive it a few more days to see if it gets better. I think disconnecting the battery worked.
Thanks again everybody!!
Last edited by matt_lowry123; Mar 7, 2013 at 10:15 AM.