Which o2 sensor?

[Adam Berger]

I am looking at buying some new upstream o2 sensors for my 99 4.0L SOHC. I looked them up on the Rockauto site and to my surprise, there is lots of them. Does anyone know what type I should buy? I looked at my original ones and noted that they are the 4 wire type, but that's all I know about them. As I live in Australia, I can't afford to buy the wrong ones. At $60 to ship them, it would be an expensive mistake. Mind you, it's still cheaper than buying them here.
Another thing I noticed on the Rockauto site, they list two 4 litre engines, each with a different letter in brackets. What's with that? How do you know if you have an "E" or an "X"? Thanks anyone that can help.

 

[Alec]

1) You could have 3 or 4 O2 sensors: If you have 4 cats then you have 4, if you have 2 cats then you have 3. You probably have 4.
2) I think the "E" or "X" is the 8th letter of the VIN. E is SOHC, X is OHV.

 

[Adam Berger]

Thanks for the info on the lettering. I believe I only have two cats, so does that mean I only have one after the cats? Anyway, I'm not interested in that one. I'm concerned with the two before the cats. Do you know if they have numbers on them? What would happen if I put the wrong type in?

 

[cjbarron5]

if you go to ford they will ask for a calibration code which is found on the drivers door or door post as long as you get them for your truck you should be fine most part stores in the states can look them up by year,make,model,and engine size

 

[griggs]

Just my 2 bits. I have had better luck with Bosch than Echlin. Have had a few Echlin O2 sensors go bad early. Also pretty darn sure you have 4 wire sensors. But be careful, even some 4 wirs sensors have different electrical connectors for different year vehicles. Maybe the Ford dealer will give you a cost break and then you are pretty sure of getting the right parts. - Jerry

 

[griggs]

Another thought. Try this link for Ford parts http://fordpartsnetwork.com/ I have had terriffic success getting genuine Ford parts at a fair price. The owner, Torrie, is good at getting the right parts too. Send your VIN along with an inquiry. I don't think the guy ever sleeps. Answers back soon. Now the shipping to down under ???

 

[bluesmoke]

Adam,

What's prompted you to get new O2 sensors?

 

[Adam Berger]

Bluesmoke,
I seem to be going through alot of fuel at the moment and I am just looking into possible causes. I thought I might change the o2 sensors to see if there is an effect. I have no fault codes in the computer, but I have read that o2 sensors as they age respond slower. They're not that dear, so I thought what the hey. I also trying some injector cleaner to see if that helps.
I pulled my entire injector and inlet manifold assembly apart on Sunday, just to see if alls ok. There seemed to be some weaping around the injectors which I thought maybe they're leaking. Something must be causing the car to chew more petrol. I thought about replacing the EGR valve and the fuel pressure regulator but I'm not even sure how the FPR works. It hangs off the back of the right (looking at the motor) injector rail and has a vacuum line connected to it and that's it. No return line. It's got me stumped.
I'm getting BFG Long Trail tyres tomorrow which should help which economy. I'm sick of driving on Mud Terrains anyway.
Above all that, the car runs perfectly. The motor is so smooth, starts every time and has plenty of power. I don't whether it is or not but it sounds like the engine pings slightly. I seems to happen when it's cold and when accelerating. Could this be pinging? I'm not even sure iwhat pinging sounds like. It's very slight this noise. Could the timing be out slightly caused by a faulty sensor somewhere. The question is, how can an engine that runs so well have a problem?