Help reading codes.

[tungsten]

Looking at a 2007.5 Yukon. Owner says stalls sometimes on cold start. Start again and all is good. Any help with theses codes? Not sure what reader it is.

 

[Marky Dissod]

P2A01 Driver side POST cat O2 sensor
P0446 It opens or closes the vent between the fuel tank and the Charcoal Vapor Canister, I think.

P1400 is related to AIRpump performance upon cold starts.
You should start by removing and cleaning both the throttle body and MAF sensor separately before reinstalling,
as well as replacing the air filter and cleaning the air filter box and tubing.

Also, check for any intake and/or exhaust manifold leaks between the MAF sensor & the O2 sensors.

 

[tungsten]

Ok thanks. Not really having much mechanical experience this seems to be not a big deal? Something relatively cheap to fix?
Thanks again.

 

[Marky Dissod]

P2A01 Driver side POST cat O2 sensor
P0446 It opens or closes the vent between the fuel tank and the Charcoal Vapor Canister, I think.

Officially, I'd say, before replacing the rear O2 sensor, address the AIRpump stuff first.
AFTER fixing the AIRpump issues, then concern yourself with the other stuff.
Greatest cost variable would likely be your choice of mechanic.

Removing and cleaning the throttle body, MAF sensor, and air intake tubing should not be expensive.
NOT keeping them clean on a regular basis will cost lots more in the long run.
Fixing any air leaks between the MAF sensor and the O2 sensors should be considered critical regardless of cost.

 

[tungsten]

Awesome thank you.