PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

p0121...searched

Thread Tools
 
Search this Thread
 
Old Jan 7, 2008 | 07:33 AM
  #1  
teke184's Avatar
Thread Starter
TECH Junkie
iTrader: (5)
 
Joined: Feb 2007
Posts: 3,183
Likes: 3
From: Key West, Florida
Default p0121...searched

was on the highway the other day...running on cruise control at 75-80mph consistently.

after 2-3 hours of driving SES pops on

drove 100miles on the highway and it seemed fine. drove it around town a few times and it was fine. then the light turned off.

did the same drive home from vacation and the light came on again under similar conditions....cruise control at consistent speed for 2 hours...

scanned it finally and came up p0121.

did some searching and this doesn't seem to be an odd problem particularly with a cam, although more common with autos.
mines a manual....

and i've drove for 3yrs with the cam and never had the code come up. i've done the same type of highway driving with no issues.

could this actually BE a bad TPS?
Reply
Old Jan 7, 2008 | 09:08 AM
  #2  
foff667's Avatar
LS1TECH Sponsor
iTrader: (2)
 
Joined: Jul 2003
Posts: 7,986
Likes: 3
From: Clermont, FL
Default

You should read this first http://www.hptuners.com/forum/showthread.php?p=101510
Reply
Old Jan 7, 2008 | 10:01 AM
  #3  
teke184's Avatar
Thread Starter
TECH Junkie
iTrader: (5)
 
Joined: Feb 2007
Posts: 3,183
Likes: 3
From: Key West, Florida
Default

been there, done that....thanks

the search turned up that page.

i don't have tuning software, i don't have any knowledge of tuning language. most of that was mumbo-jumbo.

and i also got the impression that was refering to Auto trans cars...with cams. mine is not auto.


since i've run the car for 3+ years with this cam...on the same tune...and have done many road trips with exact same conditions as this past one, but this time the SES came on.

is it possible that the TPS is actually the culprit?
i know guys love to throw the TPS in new when they see this code...according to various threads...but usually its a tuning issue.

but again, if it was tuning with mine....why would it take 3 yrs and 20 road trips to finally reveal itself?
Reply
Old Jan 7, 2008 | 10:40 AM
  #4  
foff667's Avatar
LS1TECH Sponsor
iTrader: (2)
 
Joined: Jul 2003
Posts: 7,986
Likes: 3
From: Clermont, FL
Default

Impossible to tell without a scan at the bare minimum.

ANY car auto, manual or otherwise can get the p0121 code, its not auto specific, its a code, it doesn't care what kind of transmission you chose
Reply
Old Jan 7, 2008 | 10:43 AM
  #5  
teke184's Avatar
Thread Starter
TECH Junkie
iTrader: (5)
 
Joined: Feb 2007
Posts: 3,183
Likes: 3
From: Key West, Florida
Default

what would i need to look for on a scan?

i've got scanning software to look at real time engine data.

i'm just not sure anything would show up since this doesn't seem to be a problem with around-town driving.
Reply
Old Jan 7, 2008 | 10:45 AM
  #6  
foff667's Avatar
LS1TECH Sponsor
iTrader: (2)
 
Joined: Jul 2003
Posts: 7,986
Likes: 3
From: Clermont, FL
Default

you'd want to look for the thresholds in that DTC link, but without your tuning file it makes it even more difficult because its possible your tuner tweaked those min/max limits as well(I probably would've with your cam).
Reply
Old Jan 7, 2008 | 12:23 PM
  #7  
teke184's Avatar
Thread Starter
TECH Junkie
iTrader: (5)
 
Joined: Feb 2007
Posts: 3,183
Likes: 3
From: Key West, Florida
Default

i can't figure out why a problem with the tune would take 3yrs to show up?
Reply
Old Jan 7, 2008 | 12:35 PM
  #8  
foff667's Avatar
LS1TECH Sponsor
iTrader: (2)
 
Joined: Jul 2003
Posts: 7,986
Likes: 3
From: Clermont, FL
Default

neither can I but I'm just trying to help
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-2

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-5

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-6

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo




All times are GMT -5. The time now is 04:56 PM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE