new egr no vac leaks new fuel filter dipping rpms at 1500-2500 rpms its a 98 5.,4 v8 had this problem for months i just want it fixed also says o2 sensor is bad but would that cause all this lean codes and all

 

o2 Sensors can definately cause lean codes. The ECM uses the readings from the 02 Sensors to adjust the mixture the injectors throw. Your o2 sensors are saying the truck is running rich, so the ECM issues orders for less fuel. Thus the lean condition...

Something like that anyhow.

I'm not a mechanic, but I saw one on TV...

 

Engine codes can tell you one thing but problem caused by another component that has an effect. Had same issue. Mine turned out to be the Evapoartive canister. Part of the fuel and emmissions system. Also sometimes when one overfills the gas, some gets into the vent tube, also connected to the evap canister, and creates the same condition. Anyway...the carbon filled canister traps vapors. They can get clogged and throw the codes for O2 sensors. BUT in my case the hose to the evap canister had come loose. Put it back on, no more problems. Evap is next to the gas tank. Discovered my situation with the bed off the truck tracking down a stuck gas guage. The loose hose was staring me in the face so to speak...