i have replaced my front 2 o2 sensors that are before the cats. still get this code. replaced maf. cleaned throttle body (BTW this smoothed out my idle a lot!) changed my plugs, took my fuel injectors to DR Injectors and had them tested and cleaned. dont know what else could be left??

car is STOCK! except MD plenum spacer.

 

Bump help

 

Are you sure there aren't any exhaust leaks? Failing cats? (that would usually be a 420 or 430 tho) I would recommend getting the AFR's checked. Could be that its actually running wierd and needs a tune.

 

How would I check that? What would cause this to mess up?

 

It's stock so I don't understand why tune would be needed

 

you have a plenum spacer.. that usually won't cause any issues but idk. There's no way to diagnose this over the internet.. it could be anything, even faulty wiring causing it to short out. but I would check the air/fuel ratio (either on a dyno or by datalogging) and see if its actually running rich/lean as a starting point

 

Try this:
Connect a vacuum guage to your intake manifold and compare to spec.
The primary sensors send fuel/air to the ecm,, the secondary sensors monitor the cats.
If you have a spacer, and low vacuum, reinstall and/or use a sealer.
Good luck!

 

bump! any other ideas?

 

jhc is right, you may have a vacuum leak ... check all vacuum lines ... you can also smoke the intake manifold which would cause said smoke to sneak out of any cracks/spaces on the intake path

 

Yea smoked it out. No vaccumne leaks. Could it be the rear o2 sensors?