Exhaust Back Pressure

[Phone Man]

Hello all. I just got an exhaust back pressure tester because I suspect my engine is running like crap because of a possible clogged cat. So I hooked it up and of course the results are not what I expected.

The gauge fluctuates like crazy...not steady like in every other description and video I have seen and I cant find an explanation for the readings.

Here is a link to a quick video of the gauge. https://youtu.be/KOUNLFe7Rw8

If anyone has any idea of what this may indicate I would appreciate it.

P.S. The gauge acted the same way on both front O2 sensor ports. I didn't do the back ones.

Thanks

 

[ccapehartusarmyINF.(ret)]

wouldnt a clogged cat throw a code

 

[Phone Man]

Not always.

 

[SunlitComet]

I think you should get a compression tester as well as a cylinder misfire history because it looks and sounds like a dead cylinder somewhere.

 

[Phone Man]

Possible but I dont think its a dead cylinder... the sound is coming from the gauge chattering back and forth.

 

[SunlitComet]

it should not wack a mole itself that bad. I thought I heard some low end puffing fom the engine in the background. not the needle noise.