My brothers 305 92 TPI Camaro just failed emissions and we have been trying to tune the bugs out with no success

It smells really rich when idling and is idling really rough with quite pops from the exhaust. The scan tool says the BLM is 160 and the O2 is not giving a great response, but on average gravitates towards lean. 2 new O2 sensors have both given the same reading. We replaced the plugs and tested all the wires. We just pulled the fuel line and checked to see if an injector on the passenger bank was leaking, which none were after we pressurized the lines. Any idea on how to figure out what could be wrong with it? Any advice would be greatly appreciated.

 

I saw this on an engine that had a failed-shut injector. The O2 sensor sees the lean blows from the cyl not firing, jacks up the injector pulsewidth trying to correct the leanness, and the rest run pig rich.

If you can be without the car for a few days, I'd ship the injectors to Rich at www.cruzinperformance.com for flow benching.

 

I had this happen from a vacuum leak at the IAC. Housing was loose

 

The headers are leaking. Header leaks can pull fresh air into the exhaust. Header leaks also create the popping sounds. Header leaks can cause the O2 to read lean.
A misfiring sparkplug can cause similar symptoms.

 

forgot to mention that the MAP was giving a constant accurate reading that made me not think it was a vacuum issue. If the headers had a leak would i see steam leak out when the engine was cold?