AFR difference between the banks

hc_416

I actually have that same problem thou it is on a G37. I found out by a Uprev e-tune. Randy said to look for a air leak that was the size of a pin hole...

As for the two problems I noticed the first was at idle. I need to idle around 95-105% on both banks. Bank one idles correct, but bank two will idle between 90-115%.

The second problem is when I am WOT I have deavations of 1.0 AFR on bank 2 from bank one. If bank 1 was 11.00 bank 2 would be 11.80-12.00.

The only thing I found that temp "fixed" it was tighten up the exhaust, but when it came back I had the same problem on both banks now....

I believe the problem is in the exhaust somewhere. If it is in the seals, blown out hfc or broken shorty's I am not sure. My next plan of attack is to go to LTH and get rid of the seal between the shorty's and HFC. While doing that I will look at the 02 sensors and other connections.

Well I hope I could help and subbed for info. GL