Check engine light
Thread Starter
Pro
Joined: Sep 2010
Posts: 707
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From: Murrysville PA
Check engine light
I have been having engine problems ever since I added a ported throttle body. Check engine light would come on and the engine would go into a reduce power mode (2000 vert with 17,000 miles on the oddometer).
Fast forward: I went to a tuner last week and he identified the problem as a bad knock sensor so I had both replaced and he finished his "tune".
As I was leaving he commented that if the check engine light would come on again let him know.
How could this be ( and the check engine light has come on and then sometimes goes off) since both sensors were replaced and then a dyno tune was performed. Even with the check engine light coming on the engine does NOT now go into the reduced power mode.
Any ideas; thank you.
Fast forward: I went to a tuner last week and he identified the problem as a bad knock sensor so I had both replaced and he finished his "tune".
As I was leaving he commented that if the check engine light would come on again let him know.
How could this be ( and the check engine light has come on and then sometimes goes off) since both sensors were replaced and then a dyno tune was performed. Even with the check engine light coming on the engine does NOT now go into the reduced power mode.
Any ideas; thank you.
Last edited by bontrager; May 7, 2012 at 08:41 AM.
Tech Contributor
Joined: Jan 2007
Posts: 19,116
Likes: 1,038
From: Dyer, IN
I have been having engine problems ever since I added a ported throttle body. Check engine light would come on and the engine would go into a reduce power mode (2000 vert with 17,000 miles on the oddometer).
Fast forward: I went to a tuner last week and he identified the problem as a bad knock sensor so I had both replaced and he finished his "tune".
As I was leaving he commented that if the check engine light would come on again let him know.
How could this be ( and the check engine light has come on and then sometimes goes off) since both sensors were replaced and then a dyno tune was performed. Even with the check engine light coming on the engine does NOT now go into the reduced power mode.
Any ideas; thank you.
Fast forward: I went to a tuner last week and he identified the problem as a bad knock sensor so I had both replaced and he finished his "tune".
As I was leaving he commented that if the check engine light would come on again let him know.
How could this be ( and the check engine light has come on and then sometimes goes off) since both sensors were replaced and then a dyno tune was performed. Even with the check engine light coming on the engine does NOT now go into the reduced power mode.
Any ideas; thank you.
So after replacing your throttle body(with a ported version), you started having problems. .........and your tuner's diagnosis was the knock sensors? Perhaps this is a crazy idea.....but have you considered putting the original throttle body back on?
Le Mans Master
Joined: Nov 2005
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Since a ported TB is a waste of time anyway.
Thread Starter
Pro
Joined: Sep 2010
Posts: 707
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From: Murrysville PA
Well it was an exchange type deal. You get the new throttle body for a reduced price and you have to send your core back to them, so I no longer have it. Sorry that I went for it!!!!!!
With the labor, one trip to Chevy dealership to tell me that they did get a throttle body code ( however keep driving it and the PCM will adjust) and another $400.00 for a tune, this was a very expensive "mod".
Now this morning after my second drive the check engine light is now off including the 3rd start and drive.
I will attemp to pull codes later.
Thank you for the responses.
With the labor, one trip to Chevy dealership to tell me that they did get a throttle body code ( however keep driving it and the PCM will adjust) and another $400.00 for a tune, this was a very expensive "mod".
Now this morning after my second drive the check engine light is now off including the 3rd start and drive.
I will attemp to pull codes later.
Thank you for the responses.
Tech Contributor
Joined: Jan 2007
Posts: 19,116
Likes: 1,038
From: Dyer, IN
Well it was an exchange type deal. You get the new throttle body for a reduced price and you have to send your core back to them, so I no longer have it. Sorry that I went for it!!!!!!
With the labor, one trip to Chevy dealership to tell me that they did get a throttle body code ( however keep driving it and the PCM will adjust) and another $400.00 for a tune, this was a very expensive "mod".
Now this morning after my second drive the check engine light is now off including the 3rd start and drive.
I will attemp to pull codes later.
Thank you for the responses.
With the labor, one trip to Chevy dealership to tell me that they did get a throttle body code ( however keep driving it and the PCM will adjust) and another $400.00 for a tune, this was a very expensive "mod".
Now this morning after my second drive the check engine light is now off including the 3rd start and drive.
I will attemp to pull codes later.
Thank you for the responses.
Thread Starter
Pro
Joined: Sep 2010
Posts: 707
Likes: 0
From: Murrysville PA
All end in a "H". Did this twice.
Any further suggestions???
How do I clear these codes if "H" (history) means nothing.
Thank you.
Thread Starter
Pro
Joined: Sep 2010
Posts: 707
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From: Murrysville PA
OK, I cleared all of my history codes (found instructions) and drove this morning about 7 miles to my newest office (Paneras, a bread store) and the check engine light did NOT come on.
I will keep monitoring the situation.
That ported throttle body mod has cost me a total of about $1200.00 including the knock sensors, dyno tune and labor (including one trip to the dealership to determine why engine was going into reduced power mode, ($100.00) .
Terrible waste of money!
Hope to supercharge someday.
I will keep monitoring the situation.
That ported throttle body mod has cost me a total of about $1200.00 including the knock sensors, dyno tune and labor (including one trip to the dealership to determine why engine was going into reduced power mode, ($100.00) .
Terrible waste of money!
Hope to supercharge someday.
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Le Mans Master
Joined: Jun 2008
Posts: 5,284
Likes: 235
From: Rockledge FL
you dont need a tune with a ported throttle body and the ported one I got from bare essential racing worked perfectly no codes out of the box. I must be part of the lucky 50%. You should have pulled the codes yourself. Changing out the knock sensors takes 30 minutes in the driveway and a mail in tune would have cost you 150, not 400.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 326
From: CA.
St. Jude Donor '13-'14-'15
Ported TB's i think are a good Mod --just people expect too much from it---HP is minimal about 3-5 RWHP but the throttle response is much quicker---With a potted TB the incomig air increases--The ECM has the ability to correct the AFR and "learn out' with about 50-75 miles of drivng---In order to throw a TB realted code for this mod would mean the AFR (fuel trim) correction is past apprx 20%--It should never be that farr off with only a ported TB---make sure there are NO vacuum leaks---no intake tract leaks-Did you re-oil the air filter (if you have a CAI) very common mistake will make the MAF go crazy-- and throw codes as well--
Last edited by tblu92; May 11, 2012 at 12:10 PM.
Thread Starter
Pro
Joined: Sep 2010
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From: Murrysville PA
Ported TB's i think are a good Mod --just people expect too much from it---HP is minimal about 3-5 RWHP but the throttle response is much quicker---With a potted TB the incomig air increases--The ECM has the ability to correct the AFR and "learn out' with about 50-75 miles of drivng---In order to throw a TB realted code for this mod would mean the AFR (fuel trim) correction is past apprx 20%--It should never be that farr off with only a ported TB---make sure there are NO vacuum leaks---no intake tract leaks-Did you re-oil the air filter (if you have a CAI) very common mistake will make the MAG go crazy-- and throw codes as well--
Should I; new filters have only 5,000 miles on them.
Thank you.
Thread Starter
Pro
Joined: Sep 2010
Posts: 707
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From: Murrysville PA
OK, I cleared all of my history codes (found instructions) and drove this morning about 7 miles to my newest office (Paneras, a bread store) and the check engine light did NOT come on.
I will keep monitoring the situation.
That ported throttle body mod has cost me a total of about $1200.00 including the knock sensors, dyno tune and labor (including one trip to the dealership to determine why engine was going into reduced power mode, ($100.00) .
Terrible waste of money!
Hope to supercharge someday.
I will keep monitoring the situation.
That ported throttle body mod has cost me a total of about $1200.00 including the knock sensors, dyno tune and labor (including one trip to the dealership to determine why engine was going into reduced power mode, ($100.00) .
Terrible waste of money!
Hope to supercharge someday.
Pulled codes after I restarted the engine and was able to drive another 5 miles with the check engine light on but no other problems.
Here are the two codes (only codes) both with an H at the end (I'm sure I cleared these before).
10 PCM 1514H
28 TCS C1278H
Please advise; thank you
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 326
From: CA.
St. Jude Donor '13-'14-'15
What's making it go into "reduced power mode" or limp mode is the P1514 code
You can clear it temporarily by starting and stopping the engine 3 times---but it will come back
To clear it PERMANTLY you will need someone with a tuner like HP or EFILIVE to adjust the " ETC Predicted Airflow Table" This table monitors the airflow vs throttle position--And if the predicted airflow is beyond what a stock or mildly modded engine would produce it goes into reduced power mode---typically any car that has been cammed and that has LT's and maybe a better intake manifold will produce this code
In EFILIVE it's table C6101----Simply ADD 25-30% to the entire table and it will never happen again-----
You can clear it temporarily by starting and stopping the engine 3 times---but it will come back
To clear it PERMANTLY you will need someone with a tuner like HP or EFILIVE to adjust the " ETC Predicted Airflow Table" This table monitors the airflow vs throttle position--And if the predicted airflow is beyond what a stock or mildly modded engine would produce it goes into reduced power mode---typically any car that has been cammed and that has LT's and maybe a better intake manifold will produce this code
In EFILIVE it's table C6101----Simply ADD 25-30% to the entire table and it will never happen again-----
Thread Starter
Pro
Joined: Sep 2010
Posts: 707
Likes: 0
From: Murrysville PA
What's making it go into "reduced power mode" or limp mode is the P1514 code
You can clear it temporarily by starting and stopping the engine 3 times---but it will come back
To clear it PERMANTLY you will need someone with a tuner like HP or EFILIVE to adjust the " ETC Predicted Airflow Table" This table monitors the airflow vs throttle position--And if the predicted airflow is beyond what a stock or mildly modded engine would produce it goes into reduced power mode---typically any car that has been cammed and that has LT's and maybe a better intake manifold will produce this code
In EFILIVE it's table C6101----Simply ADD 25-30% to the entire table and it will never happen again-----
You can clear it temporarily by starting and stopping the engine 3 times---but it will come back
To clear it PERMANTLY you will need someone with a tuner like HP or EFILIVE to adjust the " ETC Predicted Airflow Table" This table monitors the airflow vs throttle position--And if the predicted airflow is beyond what a stock or mildly modded engine would produce it goes into reduced power mode---typically any car that has been cammed and that has LT's and maybe a better intake manifold will produce this code
In EFILIVE it's table C6101----Simply ADD 25-30% to the entire table and it will never happen again-----
Will call my tuner tomorrow.
Last edited by bontrager; May 13, 2012 at 10:29 AM.
