How many o2 sensors on a factory '90 5.0?

jastang

Founding Member
Nov 21, 2000
947
1
18
Little Elm, TX
The Ford parts dept just tried to tell me that there were four. (2 fore and 2 aft of the cats) I disagree with him and tried to tell him that I was pretty sure that was only on OBDII cars, which would be '96 and up.

So, assuming I'm right and there are only two on a '90, in what year did they start putting four on?
 
  • Sponsors (?)


89MustangGX said:
They're before the cats actually -- right in the very front of the h-pipe, just below the collectors.


Are you guys sure they are not between the cats...

There are 2 cats on each side..I thought I remember them being right below the first one, before the 2nd one.. :shrug:

-Smoke
 
The only way you'd have four in the car is if you bought two new ones and put them on your front seat!

I've done a few 5.0 to weird vehicles. There are two on the car, and they are after the collector and before the cat. They can't be after the cat because there isn't enough wire in the harness. Furthermore, you need to sniff BEFORE the cat starts burning up the gasses.

BTW, I'm looking at the FMPP catalog right now. The sensor and relay package (part M-12071-K302) only has two O2 sensors. They also tell you NOT to shorten the wires. They go where they go.

Go ask the parts guy if he has a nine inch for a Focus. Rear axle, that is.
 
Smokedawg said:
Are you guys sure they are not between the cats...

There are 2 cats on each side..I thought I remember them being right below the first one, before the 2nd one.. :shrug:

-Smoke

Yep, there are 4 cats on a STOCK H-Pipe, unless you bought an after market H-Pipe/X-Pipe with hi flow cats, then there would only be 2 and the 02 sensors would be before the cats I believe.

Tim