Cleaned out my cat then got a p0171 lean code

Have just been catching up on maintenance new belt , new filters still need to do pcv valve and fuel filter. Have a hole in maf screen and are planning to clean the maf. Any ideas.

Thanks MCF for leading me to cat problem.
got an 03 ss with 83000 miles

 

also the code actually came just before cleaned cat, I had to replace idle air control valve because of high idle.

 

P0171 can be triggered by a vacuum leak, a bad PCV valve, exhaust leak, sticky/stuck injector(s), dirty MAF sensor, low fuel pressure or a faulty O2 sensor.

 

if I didn't properly reattach the iac, might at be place to look for vacuum leak
have a new pcv valve but didn't get the o ring, do I need a new one for install?

 

Yes, without the o ring the pcv valve will create a vacuum leak.

 

how a dirty fuel filter for p0171...I keep getting it lately,was gonna change o2 under the hood is that the upstream one..

 

yes that one is the downsteam o2...and to the poster i would reccomend going down the things associated with that code and tackle the cheapest ones first

 

I ordered the upstream one tonite from rockauto..

 

I sprayed the egr valve around the gasket with brake clean and the engine reved up a little..

 

changed upstream o2 yesterday and got code today...