Another One....Thinking O2's (sorry kinda long)

Howdy again fellow stangers!


Car is back at it again! The idle is crappy loping erratically especially right after start up, gets better as the car runs out, however there is a good bit of vibration up to about 2500 rpm. Exhaust smells super rich, almost like if it were the pump gas itself. I have recently changed the plugs (accel), wires (FRPP 9mm) and cap/rotor (MSD). I also added an oil separator to the PCV line which I purchased from Steeda.

For awhile I have had CE codes 311 and 314 on my OBD I reader, however, neither ever caused a CEL nor any performance related issues. Now the CEL will pop on after about 5-10 minutes of cruising and will stay on. Performance drops are minimal, perhaps a little bogging from idle to 2500 then strong past that and gas mileage is about 17 city and 23-25 highway. The CEL started coming on during my trip to school (1k + miles), however, I attributed it to a vaccum line I had broke when came from a fuel line (?) on the passenger side. I would simply retape (roadside mechanics) the vac line back up and the CEL would go away, however, I as I completed my road trip the CEL came on and the vaccuum line was not disconnected, the vac line is now fixed and the CEL continues to pop up. At one time I did get a code for insufficient EGR flow but only once and it hasn't happened again.

So...I am thinking it may be the o2 sensors which are on the fritz. Does this make sense or would it actualy be the thermactor air control system which the codes are for? I plan to go out and check some stuff out in the morning so I am wondering what to look for. How much is involved in switching out the o2's, how much do they cost and what exactly am I looking for? If its the air control system why would it cause performance loss??? I have also noticed a lot of heat from the center console at times and a funky smell from just in front of the firewall, which I have attributed to perhaps a dead animal my gf ran over although as time goes on I think it may be something burning.

Geez, these posts are always so long...sorry for that, and thanks for the help! I will check replies in the morning and go out and have a look at it. I can take all the pictures, audio you need. Thanks guys!
 
AFAIK, the smog codes should not affect drivability.

New lambas are ~40 bucks each. If they are not seized in, they can be easy to remove - do check first. On mine, the morons put the H-pipe in goofy and the pass O2 nearly hits the frame. :bang:

They make a special socket for removing them if you dont have a ton of tools around. Your milage is pretty decent - I am not sure O2's are the answer.
If you experience any of the symptoms at WOT, remember that the input from the O2's is ignored during that time, so the issue is likely elsewhere.

The smog system being funked can contribute to some exhaust smell, as the catalyzation is not quite as efficient w/o that air injection.

If the EGR is passing inert gas into the chambers at idle, that can create a lumpy idle. The valve can get carbon build up and not seat all the way (being open a little). Long shot on that one.

You might have roadkill cooking on your exhaust. :barf:

Good luck John.
 
If the car runs better once it's been running for a while, you need to check out your MAF/IAT/ECT sensors. The MAF/IAT may need to be cleaned and your ECT may be bad. O2's are likely fine.

Do a search if you don't know how to properly clean the sensors and test the ECT.
Scott