Running lean on right and left banks

[JT624]

My check engine light came on just before I hit 130k on my 2000 XLT and the idle became a bit rougher. I don't have a code reader so I went to the local auto parts and all their reader told me was that the right and left banks are running lean. Could this be an 02 sensor? It's not like I can't drive the truck but I want to try to fix it myself if possible.

Any info would be appreciated.

 

[scucci]

More likely a vacuum leak. I usually use starting fluid (ether) to check for leaks while the engine is idling. Just a tiny shot of starting fluid around the manifold and connected vacuum hoses. If there is a leak the engine will momentarily speed up. It is importnat not to spray too much, and don't spray near the air intake at the air cleaner. The last time i checked for these codes it was a split vacuum hose to the pcv valve.

Scucci

 

[ExploringNC]

I had the same codes a while back, when I did the 0012M kit install they went away. Meaning I was getting an air leak threw the manifold seals.

 

[Rogers-Explorer]

I had the same codes (P0171/174) and fixed it by replacing the manifold gaskets. There are numerous posts about vacuum leaks, etc that relate to these codes, if you do a quick search it won't be long before you find lots of info.

Good luck.

Cheers, Roger