What codes would bad o2 sensors bring?

 

Can someone tell me why the guys at Alantic claim that all 4 sensors are the same when RAVE says up and down stream are different. I've bought several from ebay and no one seems to know what they are selling if the RAVE is correct.

 

they are the same sensor different plugs, go on amazon .com they have the cheaper prices on OEM O2sensors

 

Hi
I about 18 months ago I finally solved the problem of Lean Mix in banks 1 & 2 i.e. P1171 & P1174. It was only after I had changed just about every ancillary component in any way connected with the air fuel mix and ignition process i.e MAF, leads, plugs, O2 sensors etc, etc. In the end I was almost driven to distraction and certainly at my wits end.

All I knew was there was some source of unmetered air getting into the intake side but I could not track it down. Then it occurred to me that there was one place I had not checked, ..............anyone ............. no, then I tell you. The fuel injector seals .......yes really. At the end of each injector there is an 'O' seal with a heat guard protecting it from the ignited fuel. Mine had been in the car from the factory in 1999 and never checked in all that time. They are certainly out of sight and mind in the side if the inlet manifold.

I sourced new seals and set about fitting them (but broke one of the heat shield in the process and had to get a replacement 2nd hand injector). The car ran better than it ever had in the 5 1/2 yrs I'd owned it.

SO do not over look injector seals when looking for sources of unmetered air leaks and a sure cause of P1171 & P1174.

For those who are unsure about where or how to change the O2 sensors here is a link to a post in another forum which I put up some time ago.
D2BC.co.uk ? Login

Also on the point of air leaks I posted this to show how to renew the vacuum connection at the plenum.
D2BC.co.uk ? Login

The O2 sensors on NAS D2s may look similar, but their construction is slightly different quite apart from the fact that the front ones have orange plugs and the rears have grey plugs so that you can't interchange the 2. Note the differences in the tips in the sensors in the photos.
http://thumbs2.ebaystatic.com/d/l225...kgd1RCeduw.jpg
https://encrypted-tbn0.gstatic.com/i...KO4QExlAeho51U

 

Wow, went through and read all the posts. Lot's of great info. I wanted to chime in at what I got from all this.

1) lean codes are normally un-metered air from a vac leak
2) intake manifold gaskets and injector o-rings are common problems
3) o2 sensor replacements as last resort and upstream sensors are the most important

 

I got a P0455 (evaporative emission leak) I believe was caused by a loose gas cap. This was followed by P1174 (fuel trim bank 2) along with a temporary loss of power (not a misfire, more like a loss of fueling). Then P0150 (bank 2 O2 sensor circuit problem). I decided to replace all 4 O2 sensors since I do not know when they were replaced (I bought a repo). I got Bosch from Amazon, 2 fronts and 2 backs. When I pulled out the fronts they were generic with butt splice connectors, and were mismatched, 2 different sensor styles. The Bosch sensors had the correct connectors and the right length wires, great fit.
After changing the O2 sensors I got a P0304 (misfire cyl. 4) and a flashing check engine light under acceleration. I swapped the plugs and they all looked about the same, 4 looked maybe a little leaner but not by much. Installed Bosch Iridium 9652, cleared the codes, and problem seems solved. The engine seems to run smoother and have not had a code all day.
I think I will replace the wires and valve cover gaskets while I have the intake apart next just so I know where everything stands.