Back again with my 2000 ford ranger xlt 3.0 auto

It's running great other than on the highway and at higher speeds it seems like it's starving out for air, when I hit a hill or heavier load at highway speeds I have noticeably less power and it sounds different kinda louder, like it's not getting enough air.

What are the best methods of testing this other than buying a backpressure tester, open to any suggestions for testing or suggestions for what the issue could be.

 

$20 vacuum gauge can tell you if exhaust is partially clogged, and its a good tool to have in any case

Good tests to do here: https://www.gregsengine.com/using-a-vacuum-gauge.html

When exhaust is clogged new air/fuel mix can't flow in so you lose power
You can do a few tests for that once vacuum gauge is hooked up, at the end on above site

But you can also hold RPMs steady at say 2,000rpm(doesn't have to be exact) and if vacuum starts to slowly drop then exhaust is clogged

Same as testing fuel pressure, $30 gauge, if it starts to drop with RPMs held high then fuel filter is clogged or fuel pump is weak, which will also cause power loss at speed or high HP demands

 

Taking forever to get around to this project due to others.

Finally got a backpressure tester im going to try and I also hooked up my obd2 bluetooth scanner and on my bank 2 sensor 2 o2 sensor i'm reading 1.3v constant which doesn't sound right, bad sensor or possibly confirms the cat is clogged? Going to run the backpressure tester as well

 

Back pressure tester?

Just use a vacuum gauge, easy to test for clogged exhaust

 

 

It has a low pressure gauge with a threaded oxygen sensor fitting, only cost like $30.

 

Get a vacuum gauge, way more uses, one of my favorite tools for gasoline engine diagnostics

Good read here on using one: https://www.gregsengine.com/using-a-vacuum-gauge.html

Same price or less than listed product, and no installation hassle assuming you can install a "T" on a vacuum line :)

 

Any input on the downstream o2 sensor reading a static 1.3v ron?

 

O2s have 4 wires, they are heated O2s so 2 wires are for the heater inside, 12v and ground wire

The actual O2 sensor generates its own voltage after its been heated to above 650degF by the exhaust temp and heater
Its a chemical reaction that generates the .1 to .9volts, so not much voltage
.1v is high oxygen, lean
.9v is low oxygen, rich
.3-.4 is what you want to see on the upstream O2s

The downstream O2 should see very little oxygen, so it stays about .8v after warm up, the Cats should burn off most of the oxygen

So now you know what I know, and I can't say why you would see 1.3v from an O2 sensor

If you are using an OBD reader/scanner? if so then unplug the O2 sensor in question and then see what Reader says after that, it may be reading the wrong data, if you still see 1.3v with O2 unplugged...........................well the 1.3v wasn't coming from the O2 sensor