Making an order, what to buy for my 85K Engine

[macker123]

I have recently purchased an 85,000 Mile 1997 Ford Explorer Sport 4.0L OHV. I have done minor things such as:

Cleaning MAS, Intake Tube,Throttle Body
Installed K&N Filter Charger
New Spark Plugs/Wires
New PCV Valve
New Fuel Filter
Replaced engine oil with synthetic

I am making an order online and here is what I am purchasing.

6 Fuel Injectors (2 of mine are faulty)
Fuel Cap (My light continually is on now)
Fuel Pressure Regulator
Transmission Gasket/Filter
Rear Axle Gasket when I change to synthetic
Serpentine Belt and Tensioner Pulley

I am contemplating whether to replace my O2's as I get horrible gas mileage and will be replaing fuel pressure regulator. But, how can you test to see if they are faulty. I was told there are 4 so that would be $200 to replace them all.


What else is cheap that I should replace to get this engine back to new. It was in a flood about 2 years ago and was fixed up, but things could have been missed. Although it seems okay just lacks power and horrible gas mileage. Partly due to the fuel injectors and I believe the fuel pressure regulator.

Any ideas on what I should replace is HIGHLY welcomed.

 

[Jason_25]

Does it have a rough idle by chance?

Any shop can check the 02's by watching how quickly they switch their readings from lean to rich and back. There may be a way to do it at home with a scanner but I don't know how.

 

[macker123]

Yes, it idled rough a little up until a few days ago and now the idle is fairly rough. It sort of feels like it is going to stall when idling but never does and when I hit the gas it is fine just less hp than normal and BAD gas mileage(180 - 210 miles per tank of gas).

 

[mjs232]

My O2 sensor went a couple of months ago, and my mechanic hooked it up to the snap on scanner, and figured out what one was bad that way because it shows the rate that they change.