Help with scan codes PO121, and PO443
Thread Starter
Launching!
iTrader: (8)
Joined: Feb 2005
Posts: 276
Likes: 1
From: springhill florida
Help with scan codes PO121, and PO443 I did a search on these codes with not much success, as I did not find an answer even though 4 threads came up. All I found basically were threads telling me what they were and how to diagnose them but not what they could possibly be.Ran a OBDII scan tool on my car last night and code PO121, and PO443 came up. I know PO443 is for the Evap emission control purge valve, but how do you go about correcting this? After I delete them they pop back up instantly.
The air pump and egr are not hooked up and havent been since I did the heads and cam but the car was tuned and they were deleted when the computer was reprogramed and that was over 4 years ago and I havent had issues with it since. What would be causing this?
I know the other code is for the TPS sensor which I have replaced several times but it just keeps throwing the same code, this one has been coming up ever since it was reprogramed???
Thanks for any help guys!
The air pump and egr are not hooked up and havent been since I did the heads and cam but the car was tuned and they were deleted when the computer was reprogramed and that was over 4 years ago and I havent had issues with it since. What would be causing this?
I know the other code is for the TPS sensor which I have replaced several times but it just keeps throwing the same code, this one has been coming up ever since it was reprogramed???
Thanks for any help guys!
Go buy Haynes Techbook "OBD II & electronic Engine Management Systems" and it will outline diagnostic procedures for trouble codes. If you need to identify the equipment you may need a vehicle specific book.
If you keep replacing the TPS sensor it may not be the problem.
If you keep replacing the TPS sensor it may not be the problem.
Check out this link there is tons of info and even possible solutions.
http://www.obd-codes.com/trouble_codes/
And here is the links to your codes.
PO443.http://www.obd-codes.com/p0443
PO121. http://www.obd-codes.com/p0121
http://www.obd-codes.com/trouble_codes/
And here is the links to your codes.
PO443.http://www.obd-codes.com/p0443
PO121. http://www.obd-codes.com/p0121
What throttle body do you have on the car? Its possible that the TPS voltage is too low when fully closed or too high when fully open. The way to check the voltages would be to back probe the appropriate wires at the tps and observe the voltage. There are a few threads on here that describe how to do this in the "bump stop" mod on the Stock TB's, some people will grind down the stop too far causing too high of voltage. Could also be a wire grounding out somewhere for the tps. Check the harness.
p0443 is Evaporative Emission Control System Purge Control Valve Circuit.
The purge valve is on the driverside of the intake.
Check the connector on the purge valve.
p0443 is Evaporative Emission Control System Purge Control Valve Circuit.
The purge valve is on the driverside of the intake.
Check the connector on the purge valve.
Thread Starter
Launching!
iTrader: (8)
Joined: Feb 2005
Posts: 276
Likes: 1
From: springhill florida
What throttle body do you have on the car? Its possible that the TPS voltage is too low when fully closed or too high when fully open. The way to check the voltages would be to back probe the appropriate wires at the tps and observe the voltage. There are a few threads on here that describe how to do this in the "bump stop" mod on the Stock TB's, some people will grind down the stop too far causing too high of voltage. Could also be a wire grounding out somewhere for the tps. Check the harness.
p0443 is Evaporative Emission Control System Purge Control Valve Circuit.
The purge valve is on the driverside of the intake.
Check the connector on the purge valve.
p0443 is Evaporative Emission Control System Purge Control Valve Circuit.
The purge valve is on the driverside of the intake.
Check the connector on the purge valve.
As for the purge valve the connection is tight to the cannister (know that I know what it is lol) however I never cut the existing line to mate with a tube to go on the pipe fitting coming out of the Weiand manifold I have. I just stuck the stock connector on it and although very stupid and lazy it help up to this point. So maybe all I need to do it cut that piece off and run a hose to it?
Post a pic of what you are talking about as far as the purge valve is concerned. The code is for a circuit problem. The electrical connector on the back is plugged in right?
As far as the TB I would check the voltages of the tps as fully closed and at wide open. If you ground down the bump stop too far you may have too much voltage at WOT. You could correct it with putting a screw in the bump stop so you can adjust how far the TB opens at WOT. I have a Stock TB laying around if you want a new one. I could port it and sell it to you if you are interested. I'll send you pics of the one I did thats on my car.
As far as the TB I would check the voltages of the tps as fully closed and at wide open. If you ground down the bump stop too far you may have too much voltage at WOT. You could correct it with putting a screw in the bump stop so you can adjust how far the TB opens at WOT. I have a Stock TB laying around if you want a new one. I could port it and sell it to you if you are interested. I'll send you pics of the one I did thats on my car.
Trending Topics
Thread Starter
Launching!
iTrader: (8)
Joined: Feb 2005
Posts: 276
Likes: 1
From: springhill florida
Yea I would be interested, send me pics and let me know a price.
I am not sure of how to upload pictures?.. I can always take one with my phone and email it to you if that would work?....
So do I have to take the throttle body off to check that?.. Not sure how to check it, would I just use a voltahe meter to check that? Excuse the dumb questions, although I did build my motor I am failry clueless when it comes to anything electrical.
Thank you for all of your help It is appreciated
I am not sure of how to upload pictures?.. I can always take one with my phone and email it to you if that would work?....
So do I have to take the throttle body off to check that?.. Not sure how to check it, would I just use a voltahe meter to check that? Excuse the dumb questions, although I did build my motor I am failry clueless when it comes to anything electrical.
Thank you for all of your help It is appreciated
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Thread Starter
Launching!
iTrader: (8)
Joined: Feb 2005
Posts: 276
Likes: 1
From: springhill florida
That looks a lot better than my attempt at porting LOL. I think that might be the route I choose to go, it might be a week or two before I can do it though. What town are you in If I would rather pick it up?..
I will try and email you a pic of what mine looks like, as well as the evap and what I was talking about.
I will try and email you a pic of what mine looks like, as well as the evap and what I was talking about.
Thread Starter
Launching!
iTrader: (8)
Joined: Feb 2005
Posts: 276
Likes: 1
From: springhill florida
Found what the Evap code was from, are you ready because this is how stupid I am LOL. I didn't have the wire pluged into the canister, I guess when I took everything apart to polish the manifold and valve covers I left a few things un buttoned. Well at least one of them is taken care of, next step a new throttle body.
Thread Starter
Launching!
iTrader: (8)
Joined: Feb 2005
Posts: 276
Likes: 1
From: springhill florida
You know, I'm wondering that since I now know what the bump stop actually is I never touched it when I tried p&p the tb. The throttle body has always opened just past parellel ever since I put on the weiand manifold. There has also always been some slack in the cable so I wonder if it needs a spacer between the tb and manifold. I also noticed that the bolt sticks far outside the bolt hole onto the egr. I have been trying to find people with this manifold to see if they have had similar issues?
You shouldnt need a spacer for the TB. You would only need one if the TB was a different bolt pattern than the manifold. Read this thread as far as checking the voltage on the TPS. https://ls1tech.com/forums/generatio...g-install.html
Do you have a stock throttle body? It should open almost parallel but not all the way or past parallel unless someone has already done a bumpstop mod on it.
Do you have a stock throttle body? It should open almost parallel but not all the way or past parallel unless someone has already done a bumpstop mod on it.
Thread Starter
Launching!
iTrader: (8)
Joined: Feb 2005
Posts: 276
Likes: 1
From: springhill florida
I printed that thread out and I am going to give it a try this saturday. It doesn't look like it was ever messed with, I just thought it might be an option since the cable has some slack and the bolt comes through pretty far. Either way I am going to use that thread to check the voltage and see what happens, I will keep you posted.
Thanks!
Thanks!
