multiple trouble code! Help!

[robstor]

I have a 2004 Denali with these codes,
p0101, mass air flow performance
p0332, knock sensor signal frequency outside normal range
p0430, oxygen storage ability of catalyst below calibrated threshold
p0446, evaporative emission vent system performance.
Any ideas on what or where to start?

 

[ezdaar]

Clean maf,
Pull knock sensors, clean rust out of block and off sensors. Try them again or replace them.

other 2, Im sure others here will chime in.

 

[robstor]

thanks I try that.

 

[kschumake83]

Start with the cheap stuff, a lot of times the computers will throw seemingly unrelated codes but they are all for one problem. As stated before, I would clean maf, then check for vaccume leaks, then replace or clean knock sensors. Hopefully these will take care of it, the one code looks like a bad cat code so hopefully its related to the maf or knock sensor codes.

Edit: and its probably your gas cap that is throwing the 446.

Sent from my Nexus 7 using Tapatalk 2

 

[robstor]

Yeah I was thinking gas cap too. Thanks for the input.