Po443 code - 2000 Cadillac DeVille

They are all Evaporative Emissions Purge Valve and Solenoid related

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https://www.google.com/search?q=PO443

https://www.google.com/search?q=PO496

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EVAP Purge Control Circuit

http://www.autocodes.com/p0443_ford.html

Try a new gas cap, that is usually the culprit. Around $20 on up for keyed at any part store. And easy to put on.

code p0443 refers to EVAP canister purge valve--circuit malfunction===causes --wiring---EVAP canister purge valve--ECM

code p0451 refers to EVAP pressure sensor --range/performance problem===causes --EVAP pressure sensor

code p0135 refers to heated oxygen sensor(HO2S) 1 bank 1 heater control --circuit malfunction===causes --fuse--wiring--HO2S ---ecm

basically the HO2S sensor is not stable and altering the air/fuel mixture settings for the ECM and this is not being helped by a faulty EVAP purge valve and pressure sensor.

2008 Nissan frontier code po443 what doesit m aen on tell how to fix it how dow I find on the truck thanks

check the vacume lines

That code is for the Evaporative Emissions. It could be a bad Evaporative Emissions Canister Valve or just a bad vacuum line or my granddaughter's 1997 Ford Escort had that code and her gas cap was NOT on. Now when you figure out what one it is disconnect the battery for 10 minutes to reset the computer.

Evaporative emission control system purge control valve circuit. po443

PO102- mass air flow sensor.
PO443- Purge solenoid.
Check & clean connections, erase codes & retry, if comes back replace them.

PO440 Possible Causes:
Charcoal canister is loaded with fuel or moisture
Fuel filler cap is loose, cross-threaded, damaged or wrong part
Fuel tank, fuel filler neck or fuel sending unit 'O' ring is leaking
Fuel tank pressure sensor is damaged, disconnected or it failed
Fuel tank vapor line(s) is clogged, damaged or disconnected
Purge valve vapor line is clogged, damaged, or disconnected
Purge or vent solenoid power circuit is open (check the fuse)
PCM has failed

PO443:
Purge solenoid control circuit is open or shorted to ground
Purge solenoid control circuit is shorted to system power (B+)
Purge solenoid power circuit is open (test the ENG1 fuse)
Purge solenoid is damaged or has failed
PCM has failed

PO449:
Sames as PO443.

Hope this helps.