need help with o2's
 

Doing WOT with narrow band o2's on HPTune. from what i am reading they should be between 890-900. I'm getting low readings.
at 100kpa 4000rpm 314 mv
4400rpm 210 mv
4800rpm 282 mv
5200rpm 230mv
5600rpm 214mv
6000rpm 179mv
6400rpm 139mv
after letting out of the gas they jump to 800 range. Bad sensors??? slow sensors????
Any ideas?????

Thats way lean, you might have an exhaust leak or an intake leak. How does the car feel? The sensor slowness has no affect at WOT so thats out of the question. Im guessing exhaust leak near the header collector because it it was truly that lean you would be having some serious knock issues.

There is a leak around the left collector at the y-pipe. need to get a new y-pipe. Thanks for the help.

Glad you found it. :cheers:

A leak should have a lot of impact at idle, and very little impact at wot.

Are both banks reading lean?

Sounds like the tune is off, or possibly the fuel pump is not keeping up on the high end of demand.

I'd be easy on it, until you can confirm the assumption on the exhaust leak. (just in case)