Check engine light ON
Thread Starter
Instructor
Joined: Dec 2004
Posts: 186
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From: la ca
Check engine light ON
2006 C6 Z51. and after 65,000 miles my check engine light came on. I have no serious mods on the car anymore except for B&B exhaust and Vararam intake. What should I do besides take it to a mechanic with a OBD reader? Could it be a bad sensor. I keep up with all the maintenance. Suggestions? Guidance? What to do?
Last edited by Sinister Evil; Mar 17, 2009 at 09:20 PM. Reason: mistake
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
If you have OnStar you could ask for a diagnosis from the code. If not, then someone with a code reader is the only option. I think Autozone might do free code reading if there is one near you. Or there is always the dealer. Good luck, let us know what it is. 
Pro
Joined: Aug 2008
Posts: 523
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From: Oak Harbor (Whidbey Island) WA
Auto Zone has a scanner that they will let you use for free. This will also reset the light. You can also reset the Check engine light be disconnecting the positive battery cable. Leave it disconnected for around 15 minutes and this will also reset the light. You will have to fix your windows if you disconnect your battery also.
Pro
Joined: Dec 2001
Posts: 678
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From: Equinunk Pa
I also have a 2006 Z51- 30'000 miles Just had a check engine light.
It was a Evaporation canister for the Emission system. Fixed -Light is gone.
No reason given for it to fail. Took it to the Dealer where I bought it
It was a Evaporation canister for the Emission system. Fixed -Light is gone.
No reason given for it to fail. Took it to the Dealer where I bought it
Thread Starter
Instructor
Joined: Dec 2004
Posts: 186
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From: la ca
I bought a $20 OBD II and it threw one code. It is the throttle position 1 performance code P0121. What to do? When I turned the car on again the check engine light was NOT ON but when I plugged in the OBD II it threw that one code P0121.
Suggestions? What do I have to fix? I don't want to erase the code until I address the problem.
Suggestions? What do I have to fix? I don't want to erase the code until I address the problem.
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
Here is some reading material but I'm thinking a trip to the dealer is at hand:
http://www.obd-codes.com/p0121
http://www.obd-codes.com/p0121
Thread Starter
Instructor
Joined: Dec 2004
Posts: 186
Likes: 0
From: la ca
I never cleared the code, but the check engine light hasn't come on. Thanks RickT. I'm off to the dealer on Saturday morning just to make sure....since my car is out of warranty I'm sure they are going to try to make some $$ at the dealer.
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Race Director
Joined: Oct 2004
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I bought a $20 OBD II and it threw one code. It is the throttle position 1 performance code P0121. What to do? When I turned the car on again the check engine light was NOT ON but when I plugged in the OBD II it threw that one code P0121.
Suggestions? What do I have to fix? I don't want to erase the code until I address the problem.
Suggestions? What do I have to fix? I don't want to erase the code until I address the problem.
These are wear parts. Internally, there is an arm with a conductive brush that moves over a resistive substrate. With repetitive use, the brush wears down and the resistive substrate wears away. Eventually, the contact becomes noisy, intermittant, or fails entirely. The ECM throws the code when this happens. Sometimes you can extend the life of the sensor by using a product called Quietrol to clean and lubricate the resistive substrate. But that's a temporary fix at best. The correct fix is to replace the TPS.
Race Director
Joined: Oct 2004
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Auto Zone has a scanner that they will let you use for free. This will also reset the light. You can also reset the Check engine light be disconnecting the positive battery cable. Leave it disconnected for around 15 minutes and this will also reset the light. You will have to fix your windows if you disconnect your battery also.
This old wives' tale just will not die, will it? There are a number of conditions which will reset a CEL, depending on which particular code caused it. Disconnecting the battery isn't one of them.
Team Owner
Joined: Aug 2007
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From: I live my life by 2 rules. 1) Never share everything you know. 2)
St. Jude Donor '11-'12-'13, '16-'17-'18
Did you recently add Z51 badges?
There are some who believe the addition of them will throw a code
There are some who believe the addition of them will throw a code
Racer
Joined: Nov 2006
Posts: 273
Likes: 1
From: Colorado Springs CO
First: Congrats on getting great use out of your car. 20,000 miles/year = . Second: Run her to Autozone or the dealer to retrieve the code. You have no choice but to find out what you're up against...
. Second: Run her to Autozone or the dealer to retrieve the code. You have no choice but to find out what you're up against...
Burning Brakes
Joined: Nov 2007
Posts: 1,002
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From: Virginia Beach VA
Here's my story -
Went to my local friendly Chevrolet Dealer (R.K.) here in Virginia Beach and told them CEL (Check Engine Light) was on. I asked the service writer to read the code. He was more than happy to; we plugged his OBDII scanner in and we were rewarded with "P0174" "Bank 2 System Too Lean."
This appears to be a good thing and is likely caused by a random hiccup due to my CAI and Cat-Back exhaust. We decided to clear the fault via the scanner and see if it returns. I somehow doubt it will (soon anyway). So in light of this I just went out and purchased a basic OBDII scanner with read and erase capability (cheap - actron PocketScan Plus $59.00). This way I can just clear it without driving all over town next time.
Went to my local friendly Chevrolet Dealer (R.K.) here in Virginia Beach and told them CEL (Check Engine Light) was on. I asked the service writer to read the code. He was more than happy to; we plugged his OBDII scanner in and we were rewarded with "P0174" "Bank 2 System Too Lean."
This appears to be a good thing and is likely caused by a random hiccup due to my CAI and Cat-Back exhaust. We decided to clear the fault via the scanner and see if it returns. I somehow doubt it will (soon anyway). So in light of this I just went out and purchased a basic OBDII scanner with read and erase capability (cheap - actron PocketScan Plus $59.00). This way I can just clear it without driving all over town next time.
Team Owner
Joined: Dec 2003
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From: queensbury ny
My CEL just came on last week and it was a P0171 + P0174 code.To much air in or something.The AUTO ZONE scanner could not turn the light off,the GM one at the dealer did. Check your gas cap and add dry gas in case you got a batch of bad gas somewhere which would set the light off.
Thread Starter
Instructor
Joined: Dec 2004
Posts: 186
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From: la ca
Fixed!! I replaced the gas pedal and the CEL was gone after two starts. Then it came back on after about 3 months.......I bought a new TB with TPS and DONE!! No CEL for 5 months. If you throw enough $$ at these cars they run great!!!! I luv my 'vette!!
Safety Car
Joined: Dec 2007
Posts: 4,974
Likes: 148
From: Magnolia Texas
My CEL just came on last week and it was a P0171 + P0174 code.To much air in or something.The AUTO ZONE scanner could not turn the light off,the GM one at the dealer did. Check your gas cap and add dry gas in case you got a batch of bad gas somewhere which would set the light off.
Last edited by dpigguy; Jul 2, 2010 at 07:27 PM. Reason: spelling
Team Owner
Joined: Dec 2003
Posts: 57,408
Likes: 164
From: queensbury ny
your CEL is likely due to the MAF sensor mis-reading the airflow entering the engine. had similar issues early on. using metal a/c tape, taped off the holes in the bumper support in front of the engine compartment as well as the seam where the front fascia meets the trim at the bottom front of the air box. no more issues and that was 3 years and 25k miles ago.
Safety Car
Joined: Dec 2007
Posts: 4,974
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From: Magnolia Texas
