Throwing codes
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From: Lawrencevile, GA
Throwing codes ok so i took my car to the shop for my tranny cause i thought it was slipping but everything is fine. they give me a paper and said it has 4 codes that popped up. they are P0128 (coolant thermostat temp), P0171 (lean bank 1), P0442 ( small evap leak), and P0455 (large evap leak) then they told me why i have the large leak someone broke my purge value on top of my motor next to the intake then they tried to fix with super glue. i have fixed why i have P0171 code but dont know about the other 3 codes. can anyone help i called gm and they never gave me a reason why i have them?
The P0442 and P0455 should both be fixed with the new EVAP valve, but if not, I would replace the solenoid back near the fuel filler neck. The part is $35 at the dealer, and it takes 10min TOPS to replace it.
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From: Lawrencevile, GA
how hard will it be to get to it? i ordered the value and should be in today so im hoping it fixes it but i have had the P0442 for about 3-4 months and can't figure out what it is?
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From the sound of it you already require the PURGE VALVE (engine compartment), due to a repair. If the light/code has been there for a while then the VENT VALVE (at the fuel filler neck) also will be required to eliminate the P0442 and P0445 codes.
The P0172 (lean code) is caused because you have a vacum leak that will go away once you fix the 2 valves mentioned above.
The P0128 code for thermostat temp can only be one of three things:
- low coolant
- bad coolant sensor
- improper ( 160* instead of the 180-187*),or faulty thermostat (stuck open)
The P0172 (lean code) is caused because you have a vacum leak that will go away once you fix the 2 valves mentioned above.
The P0128 code for thermostat temp can only be one of three things:
- low coolant
- bad coolant sensor
- improper ( 160* instead of the 180-187*),or faulty thermostat (stuck open)
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From: Lawrencevile, GA
the lean code i fixed already it was cause of the leaky seal on my fwi, had the same code on my last intake i had on here forgot to tighten at the throttle body when i was done. i got the purge valve tonight going on tomorrow. as for the P0128 code is there anyway to checkthe sensor or the thermostat or do i have to just replace them? and if anyone could tell me if i should go with the stock thermostat or what? thanks for the help
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using a digital volt/ohm meter, set to ohms, remove the terminal on the sensor (located just to the right of the front cylinder head (inside car looking out) before first exhaust port)
- test from outer housing to center terminal ( 0-10 ohms)
- if you have a thermometer test your actual coolant temp and compare
230*f-132ohms
140*f-667ohms
77*f-2796ohms
50*f-5670ohms
these are approx numbers so if you are close then the sensor is ok, but if not replace the sensor. If you have to replace the sensor then your thermostat is probably ok!
- as for replacing the thermostat USE ONLY the factory 187*, because the engine management system requires certain temps to be reached for specific operations (very important)
- test from outer housing to center terminal ( 0-10 ohms)
- if you have a thermometer test your actual coolant temp and compare
230*f-132ohms
140*f-667ohms
77*f-2796ohms
50*f-5670ohms
these are approx numbers so if you are close then the sensor is ok, but if not replace the sensor. If you have to replace the sensor then your thermostat is probably ok!
- as for replacing the thermostat USE ONLY the factory 187*, because the engine management system requires certain temps to be reached for specific operations (very important)
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From: Lawrencevile, GA
ok changed the purge valve and the P0445 code went away. i scaned it and all i have now is the P0442 code it is coming up as pending to. so im going to change the vent value. anybody know how hard it is to get to? i dont know why i dont have the P0128 code anymore though?
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Yes, too much air from somewhere!
The fwi you mention is it a CAI (cold air intake)? If so what make and is it a Wet or Dry type?
You are certain it is installed correctly and no leaks, and the screen is still in place in the stock MAF?
The fwi you mention is it a CAI (cold air intake)? If so what make and is it a Wet or Dry type?
You are certain it is installed correctly and no leaks, and the screen is still in place in the stock MAF?
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From: Lawrencevile, GA
yes there are no leaks i went over the whole thing 5 times. the screen is still in. i made the fwi myself its just 3" piping from autozone with rubber clamps holding it together i will try and get pics for you
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From: Lawrencevile, GA
instead of posting a new thread again about a new code my car has which is a P0521. I know its a oil pressure sensor code which I'm thinking needs to be replaced as a few members have had to do. I was wondering if anyone could tell me where its located, how hard it is to replace, or how much it is to buy? thanks in advance guys
I think it is the sensor that comes out of our oil pan. I think you can just drain the oil and replace the sensor. I think it is screwed into the pan. It doesn't look hard to do. Never had to change mine.
-Mike
-Mike
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The code P0521 is for oil pressure (out of range), it is located next to the throttle body/intake neck on the front side. There have been a few sensor failures reported on here over the years. It simply unscrews, though simply getting to it is another story!
It is not expensive(most parts counters will have/get)
If you look underneath it when it is out there is a LAST CHANCE filter for the DOD/AFM,I just remove it and clean it with throttle body cleaner.
It is not expensive(most parts counters will have/get)
If you look underneath it when it is out there is a LAST CHANCE filter for the DOD/AFM,I just remove it and clean it with throttle body cleaner.
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