Alright guys, been chasing down my car's lean condition (used a scan tool to find out my O2 is lean) Ive replaced my 02 sensor with a BOSH unit, that did not solve the problem (i assumed i had a bad O2 sensor) All vacumelines have been replaced and are routed right. im all out of ideas, I have the veracrap carb and the engine is the 2.8v6

 

exhaust leak?

 

I recently had the exasut down on the floor when i was replacing my oil pump, i saw no rust holes, and the only bolts i took apart where the hanger bolt, and the manfoild bolts.. I wouldn't rule it out, but it i highly doubt it

 

Possibly intake manifold leak. But if its a cc carb and the O2 is reading lean then it should richen up the mix...

 

Thought that as well, the car runs reall rough, possably due to a semi cloged cat (however the car passed SMOG with flying colors, so not gonna replace it just yet, if it aint broke[smog wise] why fix it? ) I dont hear any hissing, so im sure i dont have a leak. The read out that i read said. O2 lean, and thats it, NO codes, no anything, Its really got me confused. Perhaps the mixture needs to be adjusted some how? I dunno if i am correct in saying that the A/F mix screw is sealed from factory on this carb? if so what does it take to drill out and intall the screw? the strange thing is, Once the car is warm, the engine doenst idle as rough... as in, No roughness at all

 

Was the engine still cold or was it up to operating temp when you got the lean reading?