I have a 99 4.2L V6 with approximatively 126,000 miles on her. The Oxygen Sensors need to be replaced, and I've known it for a little while. I had the light go off before and replaced the one sensor that the code was saying needed replaced. This was about a year ago that I replaced the one sensor and the truck has been running fine since.

Now over the past week it has returned to running extremely rough, worse then before and the light is going off again. I am sure that it is the Oxygen Sensors that need to be replaced and I plan to replace all four sensors this time around.

My question is though, is it alright to go with the Bosch O.E. type or should I spend double the money on the ones from Ford? I want to buy four that are going to run properly like when the truck was new. I'd hate to buy something that is not going to work to the correct specifications of the truck.

 

Either way is fine. Bosch makes the Motorcraft sensors for that vehicle, so the Bosch will probably be cheaper but just as good.

 

Why not see what the code is that is lighting the CEL first, then act on that?

 

This needs to be your FIRST course of action.

Replacing all of the O2 sensors is a waste of beer money anyway.

O2 sensors generally do not cause "running extremely rough" anyway.

 

O2 sensors are maintenance items, so replacing them is never a waste of money if they are overdue. But you should see what the code is and take care of that first. There are some problems that will damage the sensors. Any time you run rich or get a misfire, it will foul the sensors and catalytic converters, so make sure you resolve all other problems too.

 

Yeah I ran the codes and it popped up as one of the O2 sensors.

Correct me if I am wrong but I had previously heard that it is better to replace all the sensors at once versus just one at a time?

 

Posting the actual code(s) would help. As far as changing, the 2 in front of the coverters should (depending on opinion) be changed every 80k or 100k miles.

 

The two "Upstream" sensors control the computer,the two downstream( behind the converters) merely tell you if the converters are doing their job.I suggest replacing the upstream 02 sensors only.If you have already replaced one of them...replace the other.

 

Tom, why the secret about the code #?
The code does not tell you what part to change more than 80% of the time.
There are several codes that have OX sensor in the discription but is not always the cause.
The sensor is the only way the system has of reporting an issue, it detects.
For example a code 174 is not usually an OX sensor but indicitive of an issue with the intake air fault.

 

Hey, sorry, wasn't being secretive about the codes. Just have not been online here lately

I'll have to get it run again, I can't remember the exact code. I went to AutoZone and had them run it but still have not had the chance to fix it yet. I'll try and run by there tomorrow and have them run it so I can tell you what it is. I have quite a few things going on, maybe we can figure it all out.

Just waiting on the second half of the month to come, if you know what I mean