Troubleshoting codes P0171, P0130, P0133 please?

[SgtAbn]

Hi Guys,

I apologize in advance for the long post but I am only trying to be detail oriented. I first had my check engine light come on and the fault codes were:
-P0171 "Bank 1 system too lean" &
-P0130 "02 Sensor Circuit Bank 1"

So I replaced my O2 sensor with a Bosch one; code still came back one. Then I replaced it with a new OEM Denso one from the auto parts store not the dealer, codes still came back on after being cleared.

Then I replaced the spark plugs with the best NGK OEM plugs (platinum $10 each) & NGK wires I could find; codes came back on after being cleared.

Then I cleaned the MAF with MAF cleaner, codes came back on. Then I replaced the MAF with a rebuilt Denso one, fault codes still came back on after being cleared in addition to the fault codes P0171 & P0130 coming back on, I am ALSO now getting fault code P0133 "O2 sensor circuit slow response bank 1 sensor 1. Hmmm.. .

My next thoughts are to replace the O2 and MAF again with ones from the dealer? Any help would be appreciated.. . thanks guys. . .

 

[steezemcqueen]

Check for vacuum leaks. Spray some brake cleaner, maf cleaner, etc around the engine bay and see if the idle changes. if so, you have a vacuum leak.

 

[the great him]

you could also hook your rig up to a smoke machine and test it that way for a vacume leak, although most guys do not have one of these, but a shop should and they should only charge about $50-100 to diagnose at most. -its better than shelling out a ton more money for parts that you probably dont need. also i would not spray brake clean around without some caution, as some brake cleans and plastic do not like one another, the MAF cleaner or carb and choke cleaner or even misting water from a spray bottle with a little soap in it would work best and not have any ill affects. just my thoughts

 

[SgtAbn]

Excellent idea! Thank you so much. I will do this Sunday or Monday and report back.

 

[SgtAbn]

I like your "better to be safer than sorry" approach, I will try this Sunday or Monday and report back. Thanks.

 

[SgtAbn]

Steeze you were right it was a vacume line issue. Thanks for the suggestion.