I bought four genaric universalfor$25 each. Should I replace all four to improve mpgor just the one that is burn?

 

All four no matter what.
For these trucks just changing one can lead to problems with the other ones down the road.
Someone might advise you against the cheap ones though, but I cant give you and exact answer on that.

 

If all you can afford are the cheap ones then use them, just do not cut the wires on the trk, cut the wires on the old ones.
Using universal ones will not give you the results of the exact fit ones.
Cutting the wires and soldering them will cause corrosion, so they wont last as long,most likely your splicewont be water tight.

 

Thanks, The cheap ones came with four crimp connectors. Should I tape them also?

The guy that sold me the truck is the one that told me the lack of power at 35 mph was b/c of o2 sensors. i plan to change the fuel filter also. anything else that could be holding us back?

 

What do you mean by cutting them??


-Houston

 

The "generic" O2 sensors do not come with a plug on the end of their wires. Just the wires. You have to re-use the plug from the old sensors you take off. To do this you have to cut the wires to the plug (on the old sensor) and then strip the insulation from the wire ends and solder or crimp these wire ends to the new wires coming out of the new generic 02 sensors. This is what is meant by "cutting them". Since these sensors are down low to the ground on the exhaust pipes between exhaust manifold and catalytic convertors they will get splash from off-road mud and water, and could cause corrosion of the joints you make in the wires where you attach the old plug and short wire ends to the new wires coming from the new "generic" o2 sensors.

 

Yes tape them, Go to Radio Shack and get some heat shrink and some liquid tape. Not sure if Radio Shack sells liquid tape but I know that Wal-Mart does.
Heat shrink the splice and them liquid tape it.

Before you change the fuel filter you will need to spray the connections with your favorite pen/lube a couple of days in advance. They rust really bad and you cannot get it off.
Once you have replaced it, then just plan on doing it once a year so it doesnt rust so bad.
Do the O2's and then the filter and see what happens.

 

Do all Disco's have 4 o2 sensors? I have a 94 model.

 

No, only DI's.
GEMS used 4 and BOCSH uses 2.
And no I do not know which way is better.

 

Probably a stupid newb question but what do you mean by GEMS and BOCSH?