O2 sensors and Lean codes

[pathology knight]

i posted a little diddy in the general section, but i guess i should formally ask the question here....

I've been getting a lot of LEAN codes, P0171 & P0174 on my car. I cleared them and cleaned the MAF sensor. Just now, i got just the 174 code, so i cleared it again.

I don't think my sensors are that old, but maybe they need replaced? i found the sensor behind the car, but not the one in front of it. I thought there was one right in front of it, but maybe i'm wrong??? Are all the o2 sensor's the same? Is there a specific one i need for the one behind the cat?

Here's what i've done (as far as mods) to the air intake/exhaust:
*Ram air hood
*WS6 lower air box
*stock (shaved) lid
*K&N filter
*3" pipe directly to TB (removed stock baffles)
*free ram air mod (side note: this gets the filter really dirty. I recovered the open space a little, and that seems to keep some of the road grime off the filter. I've got the SLP intake coming in the mail.)
*Pacesetter headers
*magnaflow hi-flow cat
*2.5" exhaust
*magnaflow muffler

also, spark plugs have 2-3k miles on them and the MSD wires are a couple years old. I also just cleaned the MAF sensor for the first time.

[pathology knight]

Re: O2 sensors and Lean codes

after some quick checking (i know...i know, i should have done this first), i found that the sensors upstream and downstream are different.

if i need to replace the downstrem sensor (after the cat) any recommendations on which one? there's seems to be a variety of options.

[ssms5411]

Re: O2 sensors and Lean codes

Anything other than Bosch. Denso seems to work fine.

[thebeewantsboost]

Re: O2 sensors and Lean codes

after the cat won't give you lean or rich codes.

[KJZ28]

Re: O2 sensors and Lean codes

Anything other than Bosch. Denso seems to work fine.

Really? I thought Bosch made really good O2 sensors. What problems did you have with them. I would like to know so I can inform others. Also I will e needing new ones soon. 113,000miles with originals.

[ssms5411]

Re: O2 sensors and Lean codes

They take a crap faster and seem to read wrong , these were my problems with them. But their Bosch wideband sensors seem fine.